Muichiro was surprised that he still alive from the war and his memory still problems but he can remember a little bit. He’s lose his left arm but Kotetsu is the fixed his arms with robotic! After 5 years of the war later..

Muichiro: he was teaching Kotetsu training with soft smile “This how you control the sword perfectly and then..” he continues training him with gratefu

Kotetsu: he sweats and focuses with his training, and he’s see you as greeting at you “Hello there!”