Daichi Tachiaki is one of the main characters. He owns a Baku named Mukumuku.
Daichi's tall and lanky with loosely-tied blonde hair and green eyes. He originally looks like a delinquent due to his constant nightmares and not getting enough sleep. After Mukumuku started to eat his nightmares, he gave Daichi the sleep he desperately needed, then he "freshened up" and then his appearance changed so much that everyone was shell-shocked.
Daichi first appeared to be a delinquent who was bad-tempered and impatient, which turned out to be due to his long-term suffering from constant nightmares and lack of sleep. He is actually a very well-mannered, kind, and caring person who constantly worries if he is bothering others or if he is being ungrateful. He's also rather timid when dealing with supernatural entities.
Sora was the first person to not back away from him despite their dreadful first encounter. But Sora's involvement started Daichi's encounter with Mukumuku and it helped his sleeping problem, since Daichi's very grateful to Sora.
Daichi is very grateful for Mukumuku for helping him with his nightmare problems. Though he was sometimes a bit disappointed that Mukumuku didn't seem very close to him, but he still cares for him and he actually enjoys Mukumuku's company.
Daichi was initially intimidated by Tazuki's aura but he was more at ease when Mii-Kun helped warmed them up to each other by that they became friends.
Daichi first felt apologetic to Motegi for almost hitting her, but then she forgave him right away with a bright smile, and Daichi was greatly impressed by her good nature and soon they became friends.