Watch This Boy Can Fight Aliens Online

*The Second OVA of Kono Dan series. They say look before you leap and make sure you can swim before you go in the deep water, but when a picture of his late grandfather falls into the ocean, Shima jumps in after it without thinking. Nearly drowning as a result, he is instead saved by a very perfect stranger... one whose strangeness extends to only being human from the waist up! For Shima, who's always felt like a fish out of water himself, it's more than just a revelation, and the young man and merman quickly begin to bond in ways neither anticipated. And yet, it's going to be far from easy sailing. After all, Shima and Isaki aren't just from opposite sides of the tracks, they're from entirely divergent species, and swimming in separate gene pools may make maintaining a long term relationship a whole different kettle of fish! (Source: Sentai Filmworks)

All hope seems lost when the world is suddenly invaded by aliens. Earth's only defense is a small three-person team known as the Special Counter-Aliens Task Force, consisting of an anonymous director, the tyrannical Shiro, and the easygoing Arikawa. The luck of the Task Force improves when Arikawa finds a teenage boy lying alone on a hill. The boy, Kakashi, is humanity's only hope—he has power previously unbeknownst capable of defeating the aliens! However, without any memories and with no knowledge on how to use his power, Kakashi is left clinging to Arikawa and Shiro as well as the only remnant of his previous life: his broken cellphone. Kakashi is conflicted by the fears and emotions clouding his mind and he calls his own motivations into question. Can he overcome his doubts and internal struggles and save the world? [Written by MAL Rewrite]