参議院さんぎいん選挙せんきょ 国民こくみんと参政さんせいが躍進やくしん 背景はいけいには“戦略せんりゃく的てきなSNS活用かつよう”

In this House of Councillors election, the Democratic Party for the People and the Sanseito Party significantly increased their seats.

We thoroughly interviewed the voices of supporters and, together with experts, analyzed the social media platforms that both parties are focusing on.

What was behind the growing support that emerged from there?

During this election period, when we cant expect anything from the established parties, our Upper House election reporting team repeatedly went to street speeches by Sanseitō candidates in Tokyo and other places.

So I went around asking the people who had gathered there why they supported him.

In front of Akabane Station in Kita Ward, Tokyo, a man in his 40s said, Up until now, I have voted for the Liberal Democratic Party or the Democratic Party for the People.

I want the burden of social security and taxes to be reduced. Man in his 20s: I think I first learned about the Sansei Party on TikTok.

Maybe because existing political parties have been in power for a long time, sometimes their systems feel outdated or their way of thinking doesnt seem modern. —Male in his 30s I choose people in elections, so Im an independent voter.

The best thing would be to put Japanese people first, so that Japan becomes a country where Japanese people can naturally live with peace of mind, and we can tell them to go out and have fun without worry. — In front of Korakuen Station, Bunkyo Ward, Tokyo, woman in her 30s I used to vote for the LDP with the hope that they would bring about change, but our voices have not been heard, and for 30 years the economy has stagnated. — Many people who had previously supported established parties from both the ruling and opposition sides said this time they wanted to vote for the Sanseitō party, hoping for something different.

The trigger was YouTube or social media. When I asked people who came to listen to these speeches how they learned about the Sansei Party, most of them mentioned YouTube or social media.

He is a man in his 40s from Nishitokyo City, Tokyo, whom I met at the speech venue.

Up until now, you say you didnt have a particular political party you supported—in other words, you were part of the so-called independent voters—but this time, videos on X and YouTube led you to support the Sanseitō party.

He said that he spreads information on his own X account by quoting statements from Sanseitō or those with similar views to the party.

A man in his 40s: Social media and such also tell us things that TV and newspapers dont report.

After seeing the content posted on X and their political policies, I felt that I wanted to entrust things to these people.

I resonated with the fact that they put Japanese people first.

Every single day, I find myself concerned about politics, looking at everyone’s posts, and giving likes and such to things I want to spread, hoping they’ll reach as many people as possible. There are also people who have increased their followers by sharing speeches from the Sanseitō party on social media.

Mr. Sagawa, who has been posting videos related to politics, such as explanations of elections and international affairs, for about five years.

I have over 100,000 followers, and in addition to YouTube, this time I also posted on TikTok.

On the final day of the election campaign, the last appeal by the Sansei Party, held in Minato Ward, Tokyo, was streamed live.

At the start, there were about 30 viewers, but during the roughly two-hour stream, the number temporarily exceeded 1,500.

YouTuber Mr. Sagawa: Since I dont know what will go viral, Im currently featuring the Sanseitō party, which is gaining momentum.

Many people want to hear real voices even if they cant go to the site, so when street speeches are streamed online, the number of comments and followers increases, which makes the streamer happy, and I think its also good that awareness of the election rises. All members actively share information. In this election, the Sanseito party fielded 10 candidates in the national proportional representation and candidates in all 45 electoral districts. NHK investigated the usage of SNS such as X and Instagram among these 210 official candidates and party members.

As a result, 209 out of 210 people, except for one, owned at least one social media account, and about 93%, or 194 people, had posted themselves or shared posts supporting the Sanseito partys policies or support at least once, meaning that every member actively used social media to share information.

Many of the widely shared posts and content were quotes from Representative Kamiyas posts or announcements of street speeches by candidates from various regions.

Another party that made significant gains, the Democratic Party for the People, resonated with its working generation policies.

On the Saturday before the election, when we spoke to people who had gathered to listen to street speeches by Representative Tamaki, Secretary-General Shinba, and others, many said they resonated with policies that focus on the working generation, such as increasing take-home pay.

A 40-year-old male company employee: I definitely relate to the idea of increasing take-home pay.

I also think its good that they are listening to young peoples voices and that the message is solution over confrontation.

In the past 30 years, Japan hasnt changed, but Im supporting them with the hope that maybe things will change. – 28-year-old male company employee Im paying attention because theyre talking about increasing take-home pay. Ive started watching various videos on social media and gradually become more interested in politics.

Considering the population ratio, I think there are many political parties that focus mainly on policies for the elderly, but I want to support the Democratic Party for the People because they listen to the voices of the working-age population. —34-year-old female company employee Many of the policies they advocate are convincing, and the gasoline tax reduction especially resonated with me. Since my parents home is in the countryside and we cant live without a car, the rising prices really hit home.

I used to think elections and politics were stiff, troublesome, and didn’t have a good impression of them, but even after becoming a supporter, it didn’t cost that much and I found it surprisingly casual and fun. — 19-year-old male university student I feel like they’re trying to move politics by raising the 1.03 million yen threshold to 1.78 million yen.

I work part-time at a restaurant, and I think it would be nice to be able to work without worrying about the income cap, since I can expect to earn more.

When I listen to their speeches, I can really feel the passionate personalities of Representative Tamaki and Secretary-General Shinba, and I get a strong impression of them as a friendly opposition party, said a 31-year-old female registered dietitian. As a self-employed worker, I always feel disappointed because even when I earn money, my taxes are high, and Im also worried about the future of social security.

After studying on my own this time, I felt that the Democratic Party for the People made the most sense to me and I wanted to support them, so I decided to participate as a volunteer.

Recently, each individual is able to feel that politics can change when everyone thinks carefully and votes. Looking into the SNS strategies of both parties, the Democratic Party for the People and Sanseito, which made remarkable progress.

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This time, using analysis tools such as BuzzSumo, we found that in the past year, there have been at least approximately 7,600 videos related to the Democratic Party for the People, which have been viewed more than 642 million times.

There are at least about 8,000 videos related to the Sanseito party, and they have been viewed more than 375 million times.

For all parties, the videos with the most views were those edited by third parties, featuring politicians statements or street speeches.

Since the Tokyo Metropolitan Assembly election, support for the Democratic Party for the People has been on a downward trend. Sansei has surpassed the Democratic Party for the People. Regarding the number of video views, during last Octobers House of Representatives election, the Democratic Party for the People gained attention for its outreach on YouTube, and many highlight clips were created. In November last year, the total number of views for related videos exceeded 90 million.

However, since the Tokyo Metropolitan Assembly election held in June, a noticeable decline in views has been observed, and as of the 18th of July, the number of views was just over 23 million.

On the other hand, the Sanseitō

Originally, most of the content was posted by the party’s official channel or its supporters, but from around May 2025, more clip videos began to appear. By June, the number of related video views had surpassed the Democratic Party for the People, reaching nearly 97 million, and as of July 18, it had reached 155 million.

There were especially many videos related to the Sanseito party that were clips from their speeches during the House of Councillors election, while the number of videos critical of the Sanseito party, as well as videos by TV stations and online media, was also increasing.

Some channels that originally posted edited videos of the Democratic Party for the People changed their content during the House of Councillors election period and mainly started posting videos of the Sanseitō party; there were several such cases.

Experts analyze the SNS strategies of the two parties: The SNS strategies of both parties

We asked Professor Fujio Toriumi of the University of Tokyo, who is well-versed in SNS analysis.

Professor Fujio Toriumi of the University of Tokyo: It can be said that this was an election in which new parties and smaller parties succeeded in appealing to voters by making good use of the Internet.

At first, the Democratic Party for the People was skillfully using social media to increase its support, but there was a loss of momentum along the way, and after that, the Sanseito party increased its presence on social media. According to Professor Toriumi, when analyzing X accounts that spread information about these parties, as of March this year, there were nearly 70,000 accounts spreading information about the Democratic Party for the People, the highest number, but by mid-this month, that number had decreased to about 20,000.

On the other hand, the Sanseito party had around 40,000 members in March, but this month it has reached nearly 90,000, making it the highest.

Furthermore, when looking closely at the accounts spreading information about the Sanseito party as of mid-this month, it was found that as of March this year, about 20% had been sharing posts related to the Democratic Party for the People, while more than half had not been spreading information about any political party. Professor Toriumi pointed out, It is highly likely that a considerable number of people who were not very interested in politics have joined.

Professor Toriumi analyzes that the background of this situation is that know-how has been accumulated through the use of SNS and YouTube videos in election campaigns, such as the House of Councillors election three years ago, last years Tokyo gubernatorial election, House of Representatives election, and Hyogo gubernatorial election, and that this know-how is now being used in the current House of Councillors election as well.

On the other hand, it was pointed out that one should be aware that, due to the nature of social media, content that attracts attention is displayed preferentially and directly linked to income in the attention economy system, that there are people who try to attract interest with sensational or sometimes false information, and that on platforms like YouTube, AI recommendation systems tend to show only similar content, such as information about the first political party you watched, making it harder to access different perspectives.

Professor Fujio Toriumi of the University of Tokyo: “The current information space is somewhat dominated by the attention economy, but since information is the foundation of democracy, isn’t it necessary to create a system that cannot be distorted?”

For example, measures such as prohibiting monetization of election-related videos during the election period are being implemented in other countries as well, and by doing so, it may be possible to create a somewhat healthier information environment.