Though during the Part 2, he was very much in love with Ririchiyo that he even hated his past self. When the time capsule is sent back into the past in Part 3, Soushi is able to help prevent the Ayakashi Kan massacre as well as his own death.
thus, Why is Miketsukami obsessed with Ririchiyo?
The truth of Miketsukami obsession with Ririchiyo is exposed. Kagerou is bored with the fact that Ririchiyo wasn’t upset to an extent, therefore telling her that Mikestukami was the one who was writing her the letters in the past. With the realization concluded, she felt that is why Miketsukami noticed her.
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