Satoshiomi Oka, the serious president of his school’s choir club, is suddenly approached by a yakuza named Kyouji Narita— "Wanna go to karaoke?"
It turns out that his yakuza group holds an annual karaoke contest, and whoever is crowned the “Worst Singer” has to get a questionable tattoo from the boss.
Desperate to avoid that fate, Kyouji begs Satoshiomi to give him vocal lessons. Reluctantly, Satoshiomi agrees and finds himself roped into practice sessions.
What will become of this strange and unlikely bond formed through karaoke...!?