Retto and the gang arrive in sunny Okinawa, where the whole class is due to enjoy some beachside fun. But there's no rest for the Super HXEROS, who are soon attacked by a nasty kiseichuu looking to absorb victims into its own body. Luckily, Okinawa has its own squad of HXEROS...and they just might be willing to share their secret technique. Mastering this skill will take some special and very naked training!