The Angel Next Door Spoils Me Rotten - Season 1 Episode 3
Reward for the Angel

Amanes mother, Shihoko, arrives at the apartment without warning while Mahiru is visiting. Amane asks Mahiru to hide, but Shihoko eventually finds her, and the two neighbors frantically try to correct Shihokos assumption that they are dating. Nonetheless, Mahiru is touched by Shihokos motherly kindness. After Amane sees how happy Mahiru is to be called by her first name, he tries calling her "Mahiru" too. From that day on, the neighbors call each other by their first names.