Are You Still Willing to Meet Me Again at the Entrance of the Tunnel?

In order to save his sister who died unexpectedly, high school student Kaoru Tano breaks into the "Urashima Tunnel" where time flows far faster than the outside world. After the secret was discovered by the transfer student Kyoko Huacheng, the two formed an alliance and gradually fell in love while exploring side by side. Kaoru finally let go of her obsession and reconciled with the past. After several years of trekking, she reunited with Kyoko, who had become a cartoonist, at the exit of the tunnel.