Qualidea Code is a multimedia project by four different creative teams and publishers which launched in 2015 with 3 light novels and received an anime adaptation in 2016.
The story follows an Earth where humanity is always at war with the Unknown. The kids who were evacuated to a cold sleep facility during the initial invasion decades ago wake up from their slumber to find that they'd manifested superpowers called the "World." To protect Japan, these kids start their own battles at the cities of Tokyo, Kanagawa, and Chiba.
The 6 main characters are seen topless, including Ichiya and Kasumi.
Episode 2 Edit
The group change into swimsuits to take out an Unknown that is hiding in the ocean.