Born in Okinawa, Japan.

Mitsutoshi broke into manga in 1996 with a serialization in Weekly Shounen Jump, earning an Akatsuka Award for best new humorous manga artist. His early success came with Seikimatsu Leader den Takeshi! (1997–2002), a comedy series that ran for 24 volumes and won the 2001 Shogakukan Manga Award in the children's category.

In 2002, however, Mitsutoshi was arrested and convicted of violating child prostitution laws after paying a 16-year-old girl ¥80,000 for sex. The arrest led to Seikimatsu Leader Den Takeshi! being abruptly cancelled by Weekly Shounen Jump. His sentence was suspended after two days, and he was released.

After a brief hiatus, Mitsutoshi returned to manga in 2004 with Ring, a sports-comedy series that ran for three volumes across 24 chapters in Super Jump magazine. His major comeback came with Toriko (2008–2016), a long-running Weekly Shounen Jump serialization that earned a nomination for the 2nd Manga Taisho Award in 2009, though it didn't take home the prize.