Aqua (アクア, Akua) is one of the three main deuteragonists in the KonoSuba series. Before life in the Fantasy World, she was a goddess of water who guided humans to the afterlife; within, she is worshipped by the Axis Order.

Described by Kazuma as possessing beauty no human could match, Aqua has light blue hair and eyes, a slim figure with ample breasts, long legs, wide hips, and blue waist-long hair that is partially tied into a loop with a spherical clip. Her B-W-H measurements are 83-56-83 cm and she is 5'2" (157cm) tall.

Aqua uses a sleeveless dark-blue feather dress with white trimmings (not too revealing, but not hiding anything), an extremely short dark blue miniskirt, a green bow around her chest with a blue gem in the middle, a translucent purple underskirt, and detached white sleeves with blue and golden trimmings. She wears thigh-high blue heeled boots over white stockings with blue trimmings.

Rem (Japanese: レム) is a fictional character from the fantasy light novel and anime series Re:Zero − Starting Life in Another World, created by Tappei Nagatsuki. She is voiced by Inori Minase in Japan[1][2] and by Brianna Knickerbocker in the English dub.[3][1] She first appeared within Volume 2 of the light novel, "The Road to Redemption Begins" in 2014 and made her anime debut in the episode "The Happy Roswaal Mansion Family", the fourth episode of the anime, in April 2016.

Rem is the younger sister of Ram and works as a maid for Roswaal L. Mathers and is a supporter of Emilia's faction. She initially and mistakenly accused Subaru of being a member of the Witch's Cult due to having the Witch's Scent which results in her killing him two times. However, after he managed to save her at the Elior Forest, she becomes infatuated with him, deeming Subaru as her "hero". Despite Subaru turning her proposal down, she remains to be one of his closest allies throughout the earlier chapters.

Rem has gone on to be, being ranked as the most popular female character in a poll conducted in 2016[4] and has become a fan-favorite within the anime, being consistently ranked in the Top 3 in popularity polls.[5] She has also won the "Best Girl" category during the 1st Crunchyroll Anime Awards and had an official special event dedicated to her and Ram.