Xi-Shin disliked his name.
'Xi-Shin' was nearly impossible for Japanese-speakers to pronounce. Therefore, everyone he knew mispronounced it. Xi-Shin wanted to be taken seriously, but it was difficult when people thought you were named after some damn temple.
Kirihara didn't mispronounce his name. She called him "Shiba-senpai" whenever she spoke to him. Always.
The gap of that honorific was a thousand miles.
Xi-Shin ached whenever he saw her with Kaname. There wasn't anything he could do, of course. Mana had made her choice, and she was still Xi-Shin's mindbreaker. Nothing could ever change that.
But.
Kirihara didn't mispronounce his name.