Seina, a tattoo artist, is given the challenge of creating a complex tattoo design by his unusual client, Jin. Although initially bewildered, Seina feels a sense of pride that his abilities have been acknowledged. Strangely, Jin frequently involves himself in Seina's affairs, making the tattoo artist feel a deep connection with him. As someone who has left his home and has a difficult relationship with his own sibling, Seina sees Jin as a dependable older brother figure. However, Seina eventually discovers that Jin is actually a friend of his estranged brother, who enlisted his help to approach Seina.
