Japan’s debate over sovereign Bitcoin exposure moved from the fringe to the front row this week after JAN3 chief executive Samson Mow met in Tokyo with Yuichiro Tamaki, who leads the Democratic Party for the People (DPP), and Sōhei Kamiya, leader of Sanseitō.
The political substance of those conversations tracks long-running parliamentary activity by both leaders. In Mow’s words, “Kamiya-san has raised the idea of Japan holding Bitcoin reserves in the Diet and called for tax reform, reflecting his party Sanseito’s sovereignty-first stance. Tamaki-san has proposed lowering capital gains taxes on Bitcoin to 20% and exempting smaller swaps and payments from taxation, giving Bitcoin fairer treatment in law.” He then clarified that “these are activities they have done previously in the Diet.”
The Tokyo meetings were not confined to opposition figures. Mow also underscored engagement with gatekeepers in the ruling camp: “It was a pleasure to meet Satsuki Katayama at @WebX_Asia where she delivered a speech at the Bitcoin networking event. Katayama-san is a member of Japan’s House of Councillors, representing the Liberal Democratic Party (LDP) and also chair of the LDP Committee on Finance.”
Katayama indeed chairs the LDP’s Financial Research Commission and has recently fronted party policy work touching capital markets, banking supervision and digital-asset issues, a signal that Bitcoin policy sits squarely inside the LDP’s finance apparatus.
Understanding how and where the DPP and Sanseitō sit in Japan’s power structure is essential to gauging the odds of near-term policy change. In the July 20, 2025 House of Councillors election, the LDP–Komeito ruling bloc lost its upper-house majority, while smaller parties surged. The DPP won 17 seats in that contest and now holds 22 seats in the chamber, making it the third-largest force after the LDP and the Constitutional Democratic Party (CDP). Sanseitō captured 14 seats, lifting its total to 15. Those tallies translate into real leverage for both parties in an upper house where the government must now assemble issue-by-issue majorities.
Percentages tell the same story. On the national proportional list, the DPP took roughly 12.88% of the vote, while Sanseitō drew about 12.55%, confirming that both parties converted a broad base of support into seats. With the LDP–Komeito alliance short of a majority, that performance gives Tamaki’s centrists and Kamiya’s sovereigntists greater committee-level bargaining power over any crypto tax rewrite or more ambitious reserve initiative.
Within that parliamentary geometry, tax reform is the most immediate vector. Tamaki has consistently pushed to replace today’s progressive treatment of crypto gains—which can run to the mid-50s percent when local levies are included—with a 20% separate tax, and to exempt small-value payments and crypto-to-crypto swaps from recognition, a de minimis regime designed to unlock everyday usage.
At press time, BTC traded at $113,862.
