No way he can win with 〜っこない
Grammar Explanation: A strong denial with 〜っこない

As he performs one trick after another, Kaito says he’s unbeatable at magic. Aoko says he can’t win against Kaitou Kid, the magic-using thief her police father has yet to apprehend. Kaito disregards the claim and continues disrupting class with his tricks.
- 青子:
- 「なによ、かっこつけちゃって… 勝
( てっこないじゃない……」- “What's with all that showing off? There's no way he can win.”
- 「お父
( さんだって、手( を焼( いてるんだから」- “Even Dad is having a hard time of it.”
- “What's with all that showing off? There's no way he can win.”
Key Points
〜っこない is emphatic impossibility
勝
( てっこない says winning is not merely unlikely; Aoko treats it as impossible.It attaches to the verb stem: 勝
( てる → 勝( てっこない.
The target is understood from context
The line does not repeat Kaitou Kid, but the previous exchange makes him the person Kaito supposedly cannot beat.
じゃない turns the claim into a pointed assertion.
だって supports the judgment with evidence
お父
( さんだって means “even Dad”, strengthening the argument because her police father struggles too.Aoko is not just insulting Kaito’s confidence; she backs it up by pointing to someone more experienced.
手
( を焼( く = to be at one’s wits’ end with something手
( を焼( いてる is the progressive form, so her father is currently having a hard time dealing with Kaitou Kid.The idiom often implies that the problem is troublesome to handle, not just briefly difficult.