
This story isn't finished ig, but this is so... human. Love is a confusing feeling and so many times it's a painful one too. Not everything works out okay and love often doesn't have time or space to grow when you become an adult. Touji didn't get to experience love with Yachiyo and ended up dating Kiyoto on a whim, but they still shared intimate moments and memories, they formed a bond and they loved each other, and their love was real, but the love Touji feels for Yachiyo is also real.
Love doesn't go away that easily. The regret for not realising his own feelings before it was too late made Touji never forget Yachiyo, even when he was in a happy relationship. It's a situation that is painfully emotional and with whatever Touji chooses to do, it won't be a perfect happy ending for any of the people involved.
It's such a sad story, one that shows how pulling other people in between their problems (Touji 'using' Kiyoto to forget/see if he loved Yachiyo) have lasting consequences in the future. The motives for the start of their relationship was already wrong, but they found peace in each other. Decisions are hard to make and feeling are hard to get because they are often so abstract.

I can understand why the MC acts the way he does, putting Yihan as his priority and keeps being oblivious to the toxic shit between them, but like, he should at least be friendly with Jinwoo, who helped the MC so much without him even knowing. "The one I love is already set in stone" says the MC, but he could at least be a normal fucking person and do the bare minimum that is replying to a simple text from Jinwoo... and if you truly loved Yihan you would not stand still as he gets married, even more so if he hid the fact he was already supposed to marry the girl all that time ago. Keeping secrets in a relationship is what destroys it, you should have trust in your partner, trust that he would accept and help you under any circunstances. Yihan was not honest in his relationship, and he never planned to be, even if he didn't end up marrying later on, it would still not work out as the secrets between them would pile up.

He's honestly annoying cuz he keeps playing this jealousy game, flirting with the other esper in front of the MC without batting an eye and not caring about him at all romantically, and then when the MC is about to resign he pulls the "you're not my guide anymore, I belong to the MC" bullshit, like, if I was him I would quit on the spot like wtf( ̄へ ̄)?? Cuz stay with your old S-class guide that abandoned you, cuz I'm outttt ╮( ̄▽ ̄)╭
THIS IS SO CUTE IM ACTUALLY GONNA CRY WHEN IS IT GOING TO BE MY TURNNNN??!!?!? (/TДT)/