For context, in the game there are blurbs on loading screens that sometimes show "secrets" of the girls. Haru Urara's "secret" is that she can't pronounce the word "雰囲気/fuinki" lol.
The correct pronunciation is "fun'iki", but this word is sometimes pronounced "fuinki" by children (and some adults) because it is difficult to pronounce. This emphasizes the infantile nature of haru-urara.
