Shizukanaru Don – Yakuza Side Story (静かなるドン) is a Japanese manga series written and illustrated by Tatsuo Nitta, about a Yakuza boss who works in a lingerie manufacturer during the day. It started serialization in Jitsugyo no Nihon Sha's seinen magazine, Weekly Manga Sunday on November 15, 1988.[1] The manga was licensed and published in Taiwan by Da Ran Culture before being transferred to Sun Ho Culture.