Akiba's Trip 2: Shizuku Tokikaze

Shizuku is the female protagonist, she's an little girl with purple braided hair with a mysterious power and a member of Nighteater, an mysterious clan who knows sacred teachings and an similar race to the Synthister, a group of synthetic and modified humans that are artificial vampires after being experimented by unknown scientists and gain tremendous physical abilities and intelligence, as well as immortality but their weakness is that unlike normal humans, Synthisters are vulnerable to sunlight if their whole skin is exposed during the daytime, purifying their flesh. Shizuku came to Nanashi’s (default name for the main protagonist) rescue just in time before he was being used as an guinea pig by Soga Kagutsuki (the main antagonist of the game), gifting him a kiss that helped take the sinister out of his Synthister. She then later became an member of the Akiba Freedom Fighters, a group of otaku fans that acts as a protection force in the Akiba's series. Her personality is while calm, cool and level-headed, she never comes across as, stoic, cold or heartless. This is from the animated opening of the game, I made this gif myself with SHAREfactory on my PS4.