OVA bundled with 4th volume of manga.

Three weeks after the incident that left Captain Napolipolita's ship balancing on top of Graviton City, A-Ko and the gang go on summer vacation. While A-Ko ponders losing some weight and B-Ko devises another plan to defeat her redheaded rival to win C-Ko, Napolipolita and Spy-D experience severe homesickness - begging for a way to return to their home planet. Meanwhile, Hikari Daitokuji - B-Ko's father and the CEO of the Daitokuji Financial Group - arms the local military with new mecha to attack Napolipolita's ship and obtain its advanced technology. (Source: ANN)

Minky Momo travels to an island where she finds a land of children and gets tangled up in an absurd, no-holds-barred standoff against the world's nations. Has "Dr. Strangelove" references.

With things such as story out of the way, Higurashi cranks up the fanservice with Kira, a new OVA series to commemorate the series' 10th anniversary, featuring nail-biting situations such as Rika and Satoko becoming magical girls to battle evil magic crime syndicates with the help of their trusty squad of cheerleaders, among other things. The excitement may be too much to handle. Do you dare step inside the... "different" world of Higurashi no Naku Koro ni Kira?