An all-around athlete with 万能

Kanji Explanation: Ability and capability with 能

Urushi asks Rin about what Ayumu was like in middle school.

うるし:: 「真面目(まじめ)だけど少(すこ)し抜(ぬ)けてていつも真剣(しんけん)で勉強(べんきょう)苦手(にがて)でスポーツ万能(ばんのう)か」; “Serious but a bit absent-minded, always earnest, struggles with academics, but excels at sports, huh?”; Literal: “Serious, but a little scatterbrained, always earnest, bad at studying, and all-purpose at sports, huh?”

Key Points

1万能(ばんのう) here means “good at everything” within one area

In this scene, 万能(ばんのう) means Ayumu is an all-around athlete, not that he is universally capable at literally everything.

2The sentence is a rapid list of traits

Urushi strings descriptions together with 〜て and omitted pauses, giving a quick rundown of what he was like.

3Final か marks Urushi’s reflective “huh?”

The ending か is not a formal question here so much as a reflective reaction as she pieces the picture together.
That is why the translation ends with “huh?” rather than a direct information-seeking question.

真面目 (Serious)

真面目(まじめ) means serious, earnest, or diligent rather than joking or insincere.

真剣 (Seriousness)

真剣(しんけん) means serious or earnest. Literally, it can mean a real sword rather than a practice blade.

勉強 (Study)

勉強(べんきょう) means study or the work of learning something.

苦手 (Weak point)

苦手(にがて) means something one is bad at or someone one finds difficult to deal with.