Uchiha's classmate Obito has a secret. He has another name in another world called Sawada Obito.
Tsunayoshi from the Sawada family has a secret. He has another name in another world called Kudo Tsunayoshi.
Kudo's Shinichi classmate has a secret. He has another name in another world called Saiki Shinichi, and his classmate Kuroba Kaito looks exactly like him.
Kusuo's classmate from Saiki's family has one... Well, he confessed it directly to his family. It's half a secret. He also has a name in another world called Kuroko Kusuo.
Kuroko's Tetsuya classmate has a secret. He has another name in another world called Atobe Tetsuya.
Keigo's classmate from the Atobe family also has a secret. He has another name in another world called Uchiha Keigo.
The relationship on the surface is that Obito is Tsuna's younger brother (Obito's body in Tsuna's world has shrunk to five years old), Tsuna is Shinichi's younger brother, Shinichi is Saiki's cousin, Saiki is Kuroko's cousin, Kuroko is Atobe's older brother, and Atobe is Obito's cousin.
Horrible cycle, you say... When will they discover that everyone around them has a secret.
