| Kohei Otsuka | |
| Native Name Lang: | ja |
| Office: | Leader of the Democratic Party for the People |
| Term Start: | 7 May 2018 |
| Term End: | 4 September 2018 |
| Co-Leader: | Yuichiro Tamaki |
| Predecessor: | Party established |
| Successor: | Yuichiro Tamaki |
| Office1: | President of the Democratic Party |
| Term Start1: | 31 October 2017 |
| Term End1: | 7 May 2018 |
| Predecessor1: | Seiji Maehara |
| Successor1: | Party dissolved |
| Office2: | Member of the House of Councillors |
| Term Start2: | 23 July 2001 |
| Predecessor2: | Makiko Suehiro |
| Constituency2: | Aichi |
| Birth Date: | 5 October 1959 |
| Birth Place: | Nagoya, Aichi |
| Party: | DPP |
| Otherparty: | DPJ (2000–2016, merger) DP (2016–2018, merger) |
| Website: | https://ohtsuka-kohei.jp/ |
is a Japanese politician. He was a former leader of the Democratic Party for the People (DPP) and the Democratic Party (DP).[1] A native of Nagoya, Aichi,[2] he attended Waseda University and received a Ph.D. in fiscal and monetary policies and reforms.[3] Afterwards, he worked at the Bank of Japan from 1983 to 2000 before being elected to the House of Councillors for the first time in 2001.
After the 2017 general election, then-DP president Seiji Maehara faced intense criticism for his decision to disband the DP caucus in the Lower House and forcing DP members to seek re-election as members of Kibō no Tō, the CDP or as independents.[4] As a result, Maehara resigned as DP president on 30 October 2017. Otsuka was elected unopposed to succeed Maehara the following day.
In May 2018, Otsuka led the DP to merge with Kibō no Tō, forming the DPFP. Otsuka became the co-leader of the new party, along with Kibō leader Yuichiro Tamaki.[5] He chose not to run for a full 3-year term in the DPP leadership election in September 2018.
He stated his intent to leave the party in 2024, citing his want to run for Mayor of Nagoya. This comes after Seiji Maehara and a group of others defected from the DPP due to party leader Yuichiro Tamaki ambivalent stance on if he wishes to join the LDP government or continue as an opposition member.[6]