This document summarizes lessons learned from the Japanese mobile games industry. It outlines that Japan had mobile social networks and payment systems earlier than the West. It also discusses common monetization mechanics seen in Japanese games, such as gacha systems, collection/upgrading elements, and time-gating. The document advocates for improving player retention through regular events, login bonuses, and achievements. It stresses having a long-term focus and patience, as some games can take 8-10 months to reach peak performance.