This is 2020 of our era, and Tokyo II-city, sising crime. Women can no longer go to the streets alone, not being victims. Not wanting their daughter to suffer the same fate, Parents-police Tsukas Kodzuki raise her as a child. When they are suddenly killed by one of the internal fights of Yakuza, Tsukas remains orphans on the streets along with her three brothers and sisters. Without other options, he comes to the only person who he can think for help: a poker face of Ryuji widecro, his 8-year-old classmate, as well as the leader of the powerful group of Yakuza Kururami. Ryuji, whose father also became a victim of the same fight Yakuza, agrees to take it as his personal bodyguard. While they intended to find their enemy, Ryuji splits an increasing amount of debts over the Tsukasoy, using all sorts of tricks to keep reluctant Tsukas on his side.