Mokou is an immortal, and the enemy of Kaguya Houraisan. She’s broke, but staying with Kaguya and working as her maid at Eientei, even if she despises it. Even so, she forces herself to be polite to Kaguya, as she’s paying and sheltering her. She’s a surprisingly good cook. She calls Kaguya “Lady Kaguya”. She also works for Eirin Yagokoro, Eientei’s other owner. In her free time, since she can’t smoke, she usually hangs out with Reisen Inaba. She mumbles about Kaguya behind her back.