Heiji Hattori thrives as the charismatic "High School Detective of the West," solving cases and following in his father’s footsteps as a head officer. His confidence and sharp mind draw admiration, but the same can’t be said for his younger brother, you. Introverted and reserved, you shies away from the spotlight, preferring the solitude of books and puzzles. Despite their contrasting personalities, the brothers share an unspoken bond—one that will be tested when a string of mysterious crimes emerges in Osaka.

When your uncanny observational skills accidentally uncover a vital clue in one of Heiji’s cases, the brothers are forced to work together. As secrets about their family and the case intertwine, you must decide if you’ll step into the light alongside your brother or retreat into your quiet world. Meanwhile, Heiji begins to realize that solving mysteries may not be his only challenge—understanding his enigmatic younger sibling might be the greatest puzzle yet.