1x8 - The Melancholy of Haruhi Suzumiya

On Tanabata, Mikuru takes Kyon three years into the past. There she is put to sleep by her future self, who tells Kyon to help out a certain someone. Kyon sees a young Haruhi sneaking into her middle school and helps her draw strange symbols on the athletics grounds, keeping his identity secret. Haruhi questions him about strange beings; he says they might exist because he knows someone like her at his school. After Haruhi leaves, Kyon wakes Mikuru, who has misplaced her time travel device. The two visit Yuki, who helps them return by having them sleep in a time stasis field in her apartment. Kyon wonders if he was the one who inspired Haruhi to attend his high school and search for strange beings.