Absolute Duo

Absolute Duo is a light novel series that received an anime adaptation which aired in 2015.

The story follows Tor Kokonoe, a teenager who enrolls in Koryo Academy, a high school where its students battle each other with weapons known as Blaze while training to become future peacekeepers. Although most students manifest their Blazes as melee weapons, Tor's ability manifests as a shield, marking him as an Irregular. The school uses a special Duo system in which students are assigned partners and Tor finds himself paired with Julie Sigtuna, a silver-haired girl from Scandinavia who must share a room with him.

Episode 4
Tor takes a bath.

Episode 5
Tor and his classmates are testing out their enhanced stats in the school swimming pool after reaching level 2.

Episode 8
Tor is at the beach and at a hot spring.