Ryuuguu Fantastica
竜宮ファンタスティカ
At the last Houryou festival, when the oceanic Gates of Ryuuguu are believed to open every seven years, Yura discovers Nao on a beach. With no prior connection, she brings him home and raises him as her younger brother. Over the following seven years, they grow close and live happily together. However, as the next Houryou festival approaches, Nao begins to display odd behavior.