TV-Series
Description
Jyushimatsu Matsuno is the fifth-born son of the Matsuno family, making him the second-youngest of the six identical sextuplets. His name is derived from the Japanese term for the Bengalese finch, though it also incorporates characters signifying the number fourteen and the word for pine tree, following the numerical naming pattern shared by all the brothers. In early depictions, his birth order was often ambiguous, with some media placing him as the youngest, but later works firmly establish him as the fifth son.

As a young child, Jyushimatsu was depicted as noticeably quieter, gentler, and more sensitive than his rambunctious brothers. He tended to avoid rough play, cried easily, and was considered thoughtful and obedient. This compliant nature, however, made him quite gullible and easily led into mischief by his siblings, such as digging pitfalls or putting dandruff on shaved ice. During this period, he also expressed feelings of insecurity about his indistinct identity, feeling his presence among the sextuplets was the weakest because his name was never called first. In childhood scenarios, he was often paired with his brother Ichimatsu, with whom he shared a shy disposition and frequently collaborated on various activities.

A significant transformation occurred during his adolescent years, roughly between the ages of sixteen and eighteen. In an attempt to differentiate himself from his brothers and cultivate a unique persona, Jyushimatsu adopted the look of a delinquent. He affected a constant expression of narrowed, spaced-apart eyes and a bitter frown, wore his high school uniform sloppily with his shirt untucked and pants unzipped, and would pretend to smoke invisible cigarettes. This tough facade, however, was a mask for his inherently cheerful and whimsical nature, which would resurface when he was alone. This evolution was eventually resolved through interactions between his adult self and his past self, solidifying his final, more genuine persona after graduation.

In his twenties, as he is most commonly seen, Jyushimatsu is the most energetically childlike and eccentric of the Matsuno brothers. He is almost perpetually happy and over-excited, and is rarely seen in a serious state. His default expression is a wide-open smile with his tongue visible, and his appearance is marked by a single cowlick. He typically wears a bright yellow hoodie with stretched-out sleeves, blue swim shorts, and white socks. His personality is so bizarre and his actions so illogical that he is often described as being in his own genre, with his brothers and others noting he has trouble blending in with ordinary people. Despite his chaotic nature, he demonstrates genuine kindness, such as working hard to help Ichimatsu find his lost cat. However, this cheerfulness has a darker edge; he can become dangerously unpredictable and angry when set off by certain stressors, like cold weather. One recurring example of his odd logic is his annual tradition of staying up on Christmas Eve not to receive gifts, but to finally capture and tie up Santa Claus.

Jyushimatsu shares a particularly strong bond with his brother Ichimatsu. As children, they were frequently paired together, and as adults, Jyushimatsu often checks in on Ichimatsu and joins him in his activities without judgment. He is also able to tolerate his brother Karamatsu's often painful attempts at being cool without mocking him. His role in the story is frequently to inject pure, unpredictable chaos or to lighten tense situations with his oblivious joy. He keenly observes the emotions of those around him, especially Ichimatsu's unspoken feelings, and acts to alleviate the mood.

Among the sextuplets, Jyushimatsu displays the most reality-warping abilities, often bending the laws of physics for comedic effect. He is capable of spontaneous self-multiplication, creating dozens of copies of himself, and can undergo sudden muscle growth, inflating his body to enormous proportions. These feats are presented as natural extensions of his abnormal brightness and boundless stupidity, earning him the label of a human nuclear warhead. His obsession with baseball is another defining trait, and in one notable instance, he was shown practicing his batting swing over six thousand times near a cliff, an act of extreme determination that ultimately allowed him to connect with a despondent woman and help her find her smile again.