38. Is there a ban on vote buying?

Source: 
公職選挙法, 1950 (2022改正)
Public Offices Election Act, 1950 (as amended by Act No.68 of 2022)

第二百二十一条　次の各号に掲げる行為をした者は、三年以下の拘禁刑又は五十万円以下の罰金に処する。
一　当選を得若しくは得しめ又は得しめない目的をもつて選挙人又は選挙運動者に対し金銭、物品その他の財産上の利益若しくは公私の職務の供与、その供与の申込み若しくは約束をし又は供応接待、その申込み若しくは約束をしたとき。
二　当選を得若しくは得しめ又は得しめない目的をもつて選挙人又は選挙運動者に対しその者又はその者と関係のある社寺、学校、会社、組合、市町村等に対する用水、小作、債権、寄附その他特殊の直接利害関係を利用して誘導をしたとき。
三　投票をし若しくはしないこと、選挙運動をし若しくはやめたこと又はその周旋勧誘をしたことの報酬とする目的をもつて選挙人又は選挙運動者に対し第一号に掲げる行為をしたとき。

Article 221. Any person who commits any of the following acts shall be punished by imprisonment for not more than three years or a fine not exceeding five hundred thousand yen:
(i) Offering, promising, or providing money, goods, other property interests, or public or private duties to an elector or election campaigner, or offering, promising, or providing entertainment or hospitality to such a person, with the intent to secure an election victory, prevent an election victory, or secure the defeat of a candidate.
(ii) Inducing an elector or election campaigner, with the purpose of securing or preventing election, by exploiting special direct interests such as water rights, tenancy rights, claims, donations, or other special direct interests pertaining to that person or to temples, shrines, schools, companies, unions, municipalities, etc., with which that person is connected.
(iii) When, with the purpose of receiving compensation for voting or not voting, conducting or ceasing election campaigning, or for mediating or soliciting such actions, one commits the acts listed in Item 1 against an elector or election campaigner.

Vote buying is a criminal offense.