Room of Hyacinth

Part 1 of The Older Brother of the Psychic’s Little Brother series

Kageyama Shigeo has pink hair, but that's not all. He's an honor student, a sports team captain, a compliant son, and a loving older brother. Shigeo wants nothing more than to maintain this wonderful life. But with his younger brother, Ritsu, seeking more indepedence, Shigeo is forced to navigate through interpersonal relationships to understand why people want to change, and why he doesn't.

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Disastrous Life of Saiki K and Mob Psycho 100 crossover

Takes place in a hybrid world in the setting of Jujutsu Kaisen
Story notes, tags, and warnings expanded in Chapter 1