凉宫春日的消失

距圣诞节仅有8天时间，SOS团在凉宫春日的号召下，不出意料地策划了一场圣诞狂欢派对。但就在12月18日这天早晨，阿虚却发现周围的世界有了些许变化。1年9班消失不见，朝比奈学姐视其形同路人，甚至早已死去的朝仓也代替凉宫春日坐在了阿虚的后面，而春日则如同人间蒸发一般无人知晓。当他冲向SOS团的教室时，只看到了孤零零坐在角落里看书的长门有希，一向淡定自若、冷如冰霜的长门大神也变成了怯懦害羞的乖乖女。从前一日长门留下的蛛丝马迹中，阿虚判断出这个世界似乎被某人重组了一番。 　　此时的阿虚，握有连接两个绝然不同世界的钥匙，他面临着重大的选择……On December 18, Kyon finds that several traces of the SOS Brigade have mysteriously disappeared from his life. Mikuru and Yuki do not seem to recall meeting him, and Haruhi and Itsuki do not attend North High School. In addition, all the former Brigade members have become normal people. Eventually, Kyon receives a message from Yuki's alien counterpart asking him to gather keys for a program that could return him to his own reality. This starts Kyon on a journey that eventually leads him back to the night Haruhi first became interested in meeting aliens, time travelers, and espers.