Naruto and Shino have been sent on a mission to the Motoyoshi village. On the way there Naruto is complaining to Shino, as usual, when they come across an old lady. She makes a remark that even the dead laugh in Motoyoshi village. Once they get to the village they meet with Fuuta Kagetsu. He is the eldest son of Toubei Kagetsu, a wealthy land owner who has recently passed away. It states in his will that he will inherit everything on the condition that he does not laugh during the funeral. He know that this will not be possible as all his cousins and his sister Tsukiko will be doing everything in their power to make him laugh so they can inherit it all. However, there is a loophole in the will that allows Fuuta to have a stand in. He has asked that Shino stand in for him because Shino has never laughed before. Shino agrees and they have a meal later to celebrate. They meet the youngest sibling of the family, Mai Kogetsu. Just as they are about to start eating, Shino says that he will test the food for any poisons. He says that his bugs will devour any harmful poisons before it could do him harm. He eats his meal and all of a sudden, he begins to laugh uncontrollably. Shino tells them that the food has been tainted with a laughing potion. It is now up to Naruto to be the chief mourner.
As the funeral begins, Tsukiko begins her plan to make Naruto laugh. She has hired the funniest looking monk to preside over the funeral and all of the cousins take turns doing something silly in order to make Naruto laugh. Naruto is able to hold it back, barely, throughout the ceremony. Meanwhile Shino follows the old woman that they had encountered outside of town and discovers that it was her along with Mai that slipped the laughing potion into the food. Back at the funeral, Tsukiko has almost run out of options and Naruto still has not laughed. She then uses her husband in a ridiculous get up to make Naruto laugh. Just as Naruto is about to give up and laugh, Toubei Kagetsu appears. Everyone thinks it's a ghost. He plays out a scene from their childhood and everyone realizes that the family was happier when they were poor and did not have all their wealth and land. Then the old lady and Mai show up. The old lady reveals herself to be Toubei and the ghostly Toubei is actually Shino using his bug clones to play out the scene. Everyone realizes that Toubei just wants the family to get back to the way it was.