A pretty clean room with 相当
Kanji Explanation: Mutuality and appearance with 相

Hiro lets Mao move into his sister’s bedroom, as Hina is living with relatives. After, he comes up with a list of rules that Mao needs to follow if she’s to keep living there.
- 基:
- 「…さて 片付
( け…」- “Now then, cleaning...”
- 「できるのかな おまえ…」
- “I wonder if you can do it.”
- 「俺
( 陽菜( の部屋( 相当( キレイにしてたんだぞ」- “I kept Hina's room pretty clean, you know.”
- “Now then, cleaning...”
Key Points
相当
( = “quite” as an adverbHere 相当
( modifies キレイにしてた, so it means Hiro kept the room quite clean.It is not “appropriate” or “equivalent” here; the scene is about degree.
Casual sentence shape: 部屋
( (を)相当( キレイにしてたThe object marker を is omitted in casual speech.
That means “I kept Hina’s room pretty clean”, not “Hina’s room became clean”.
〜てた = casual 〜ていた
してた is the spoken contraction of していた.
It presents this as an ongoing state in the past: Hiro was keeping the room clean over time.
んだぞ adds insistence
んだ gives an explanatory or assertive tone, and ぞ makes it sound rough and emphatic.
In context, Hiro is stressing his own track record to question whether Mao can manage the room.
See Also
- Grammar: Reasoning with 〜のだ
- Kanji: Sections and departments with 部
- Kanji: Shelter and shops with 屋