Kekkaishi

Yoshimori engages in battle with the spy but the spy runs away. Yoshimori chases after him outside the school grounds but the spy runs into the forest. Yoshimori envelopes a large part of the forest with a kekkai and the spy is trapped, but then he drinks a power-up drink and strengthens himself and rips the kekkai apart. The spy swings his arm in a circle creating a mystery circle and uses the confusion to escape. Yoshimori is left with the spy's right arm as evidence.