His Uncertainty

 is the fifteenth episode of The Disappearance of Nagato Yuki-chan.

Plot
With the arrival of summer break, the Literature Club, along with Kyon's little sister, go on a trip to the beach, staying at Tsuruya's beach house. Nagato just sits on the beach playing handheld video games, but Asakura badgers her and Kyon to play with the beach ball together. Kyon is uncomfortable with the lack of conversation between him and Nagato, while Nagato enjoys the silence.

The Literature Club heads for the mountains to hunt cicadas and have a test of courage. They break up into pairs chosen by Tsuruya: herself and Asahina, Haruhi and Koizumi, and Kyon and Nagato. Asahina is nervous about the test, saying she did it before and Tsuruya set up something to scare her, which Tsuruya denies. Hearing Asahina scream, Kyon and Nagato run to the end of the test and witness Asahina passing out while pointing to a group of fireflies, which she took for will 'o the wisps. Kyon is angry at Tsuruya for not telling Asahina what they really were, but Tsuruya insists it is Asahina's own fault for repeatedly not recognizing them. Kyon and Nagato continue to hold hands in the presence of the others.

Characters

 * Kyon
 * Haruhi Suzumiya
 * Ryoko Asakura
 * Itsuki Koizumi
 * Yuki Nagato
 * Tsuruya
 * Mikuru Asahina
 * Kyon's Sister