This article explores the historical context, current legal status, social attitudes, cultural and religious views on sibling marriage in Japan. It is currently illegal under Japanese law and is generally viewed negatively due to its potential consequences on both parties involved and future generations if they were to have children together. Pros of allowing such unions include allowing families facing economic hardship or famine an opportunity to preserve their wealth by pooling resources through arranged marriages between siblings from different families, and allowing people who are deeply devoted/in love with one another an opportunity to legally marry regardless of familial ties. Cons include increased instances of incestuous behavior, disregard for societal norms regarding relationships, higher divorce rates due lack of compatibility between spouses, and long-term implications for future generations.