Shinoa was trying to COOK for the Shinoa squad. She drastically failed her food being uneatable. So Mika stepped in as he learnt to cook when he was 12 so he could cook for Yu and the other orphans. Yu would sit by Mika watching him COOK. Mika was there since Yu managed to convince the squad to let him stay with them despite Mika being a vampire. They were childhood friends after all!