Plug Cryostat

Fight Ippatsu! Jūden-chan!! (ファイト一発!充電ちゃん!!, Faito ippatsu! Jūden-chan!!?, lit. Fight, One Shot! Charger Girls!) is a manga series by Bow Ditama, which is also adopted into a television anime series of the same name that began airing on the liberal AT-X network in Japan from June 25, 2009. It features anthropomorphized characters representing aspects of charging electrical equipment. This series contains some explicit fanservice, including omorashi, which is broadcasted uncensored. The series is also released on Crunchyroll, under the title of Charger Girl, Ju-den Chan, although it is censored.

From a planet called "Life Core", which exists parallel to the normal human world, females known as "Jūden-chan" (charger girls) are patrolling the human world in search for individuals who feel depressed and unlucky. Their job is to charge these people up with the help of electricity in order to improve their mental states. Whilst normally unseen by human eyes, one of these Jūden-chan, Plug Cryostat, accidentally meets a young man who is able to see her, because she was targeting his father (his sister in the anime). This series revolves around the various antics between the main characters and the quest for this Jūden-chan to improve herself.

The female protagonist. She is a "Jūden-chan": someone from a world that is parallel to our own, capable of recharging people who are depressed or unlucky. She is however not very good at it and is a bit of an airhead. Because she has the ability to use phasing, she normally can't be seen by regular humans. This is done so she can do her job without causing distraction. She loves to watch a rather ecchi anime series called "Millie-chan". Whilst other Juden-chan focus on charging people and getting paid, Plug focuses on discovering the root of their problems and timing her charges so that they won't become depressed again.It is revealed that the boss is starting to like Plug because she has something the other Juuden chans do not have although we do not know what that property is.

Plug's fellow Jūden-chan and rival, who becomes her supervisor. She is rather serious when it comes to work and is rather annoyed with how Plug is carrying out her job. In turn, Plug finds Arrester irritating for interfering with her work and the two girls tend to fight a lot. She sometimes ends up crying, which Plug uses as blackmail material. Compared to Plug, Arrester is rather well endowed, which causes Plug to tease her about that. She has feelings for Sento from the moment she saw him, but he is rather oblivious to this. Following their first meeting, Arrester seems to have garnered a fetish for being hit by a baseball bat.After Plug is injured while charging a class Z boy she becomes closer friends with Plug.

A young man who is the only human capable of seeing both Plug and Arrester. He works at a family restaurant and has a rather short temper, which results in frequently hitting Plug (and at times Arrester as well) with a baseball bat or whatever is within reach; this has become a running gag in the series. He occasionally helps Plug and Arrester with their work, teaching Plug that the best way to find an opportunity to charge is to make one yourself. He lives with his younger sister.

Source: Wikipedia