Episode 01[]
Shinya's birthday.
Episode 02[]
Japanese[]
Takuya: "He [Tomoki] must only be in third grade or so..."
Takuya: "I'm in fifth grade! I'm older than him.
Izumi: "So we are the same age? Come on... I thought you were younger than me."
Takuya: "I'll be 11 years old soon!"
Izumi: "On which month?"
Takuya: "August."
Izumi: "So I'm older after all. My birthday is in May, so I'm three months older."
Episode 03[]
Japanese[]
Takuya: "You [Tomoki] can't. You're only in third grade, aren't you?"
- Given that Tomoki doesn't refute this claim, we can assume he's in third grade.
Junpei: "Well, I'm in sixth grade!"
Episode 08[]
English[]
J.P.: "Professor? I'm no professor, I'm only in the seventh grade."
Episode 09[]
Japanese[]
Takuya: "I have a little brother [Shinya]. He's the same age as Tomoki."
- Given that Tomoki is stated several times to be in third grade, we can assume Shinya is also in third grade.
Episode 27[]
Japanese[]
Kouji: "I'm a fifth grader now. I can't be clinging to my parents."