Shiina Aki is constantly being treated like a girl due to his feminine looks so he decides to move to Tokyo to attend middle school in an attempt to change himself. However, what awaits him in his new home, Sunohara-sou, is the kind-hearted caretaker, Sunohara Ayaka. Along with the three female members of Aki's new middle school's student council, Yukimoto Yuzu, Yamanashi Sumire, and Kazami Yuri. And so begins Aki's new life in Tokyo living with four girls.

Several people are spending their evening in a cafe. Two gossiping girls, two debating men, a bookworm and a boy, who just broke up with his girlfriend. The cafe's waitress starts a chat with him, persuading him to take a look at certain easel, while other customers begin to notice unusual things.

(Source: ANN)

When Nube and his class arrive at a small island to carry out beach activities, they heard a forbodding tale from an old man residing on the island. Legend has it that there is a creature known as the sea spider in the open seas around the island. When the creature is past 200 years old, it will turn into a monster and devour humans to satisfy its appetite. However, curiousity kills the cat and Yukime decides to pursue the authenticity of the legend. And then, a girl suddenly appears on the beach. Possessed with a strange charm, she immediately attracts Hiroshi's attention and overcomes him. Soon later, strange things start to happen to the others whereby Kyoko and Ritsuko-sensei got attacked under strange circumstances. The true identity behind the mysterious girl is questioned and the legend behind the sea creature seems to be true after all.