Sonokawa Junpei, a 19-year-old who works multiple part-time jobs to support his family, chances upon 'M', an unusually strong Jan Sen (online mahjong game) player who is believed to be cheating and wanted by the game's publisher V.Line for a huge amount of money at the family restaurant where he works, and arose to the opportunity to get the reward.

Sonokawa Junpei, a 19-year-old who works multiple part-time jobs to support his family, chances upon 'M', an unusually strong Jan Sen (online mahjong game) player who is believed to be cheating and wanted by the game's publisher V.Line for a huge amount of money at the family restaurant where he works, and arose to the opportunity to get the reward.