Responses
The fact that Caius want Kouichi to be happy is somehow selfish, but at that point, knowing that Caius knew the risk he still do it for him but it turns out he didn't tell Kouichi of what will be the cause and instead want to fulfill Kouichi's wish and at the end it's like breaking his promise to meet him again....I just hope nothing happen so seriously bad.

See, Koichi really just needed someone else to tell him to be happy for himself. He's very selfless so he doesn't even consider it and thinks first of the people who helped him and he's left behind.
I just hope everything will work okay from now on... Please. I'm hurting.