Glenn becomes a personal tutor to Unu, a girl with a troubled past that desires to obtain a scholarship for Alzano Imperial Magic Academy.
Tropes:
- Cerebus Syndrome: The story starts light-heated with Glenn and co. tutoring Unu and helping her mother, but it takes a darker turn when Unu's father, Daruhan, appears and forcefully tries to take her back.
- Double-Meaning Title: The title refers to Unu's inability to talk back to her abusive father and her inability to confess to Glenn.
- Food as Bribe: The story starts with Unu trying to force Glenn to teach her magic in exchange for the food she gave him. However, he ends up accepting food as payment upon seeing the state in which she lives with her mother, Yumis, and denying Yumis' offer of Sex for Services.
- Innocent Innuendo: What causes the girls to mistake Yumis for Glenn's girlfriend is her telling him that she will give him something only meant for adults, which refers to the brandy cake she made since it is not suited for Unu to eat due to the alcohol inside of it.
- Last Girl Wins: Discussed by Unu, who wonders if Sistine and Rumia's inability to confess their feelings or advance their relationship with Glenn will cause him to be taken by a heroine that appears later.
- Master-Apprentice Chain: Downplayed since it is only schoolwork, but Glenn, Sistine, and Rumia teach Unu magic theory, who in turn teaches Re=L so she can complete her homework.
- Noodle Incident: What Glenn did to anger Sistine till the point she led him to starve and stop Rumia and Re=L from helping him is never specified aside from that it had something to do with embezzling meal tickets.
- Simple Solution Won't Work: The reason why Yumis and Unu were unable to find a normal tutor is due to Daruhan's interfering, which causes Unu to seek out Glenn.
