Lune has long hair with trimmed bangs, and has two small horns protruding out of her head. She wears a middle school girl sailor outfit with a lab-coat on top off it. Lune has a hagoromo and a handbag, while her skull sensor is placed on top of the bag. Both of her legs, her right arm and her right hand are bandaged, with an addition of a band-aid on her left shin and a new bandage on her left hand.
Lune displays a somewhat masochistic attitude as shown that she is willing to stab and cut herself without care. She is also a bit lazy, shown when she gets annoyed and upset that she has to do roll-call, even though she did it a week ago. Lune also seems to have a sweet-tooth, since she once ordered for a coffee with heaps of sugar.
Old Conquest Arc
Lune is first seen at a Taiyaki vendor, where she orders one Taiyaki. She is then shoved by two Majima private school delinquents who then order their own taiyaki. Lune, aggravated, starts mumbling to herself, much to the two trouble maker's curiosity. She then starts to laugh evilly, stare at the two delinquents, and then pull out a box cutter. The two delinquents, scoff at this, to which Lune responds by stabbing the back of her hand (much to the delinquents shock.). She then curses the fact that she cannot kill humans even though she is a devil, but happily states that she will soon be free, and then gladly pay the debt back a thousand times over. She then proceeds to stab the back of her hand again while laughing, scaring the delinquents away.
Later, Lune receives a call from Vintage. She is asked to confirm the safety of the neighboring Vintage members. Lune responds that she had sent a message signal recently, and dislikes sending it out so many times. After being pestered to do so, she sends another message signal. As Lune checks for responses, she noticed that all the members appeared to be alright except for one named Fiore. Asking herself who that is, she noticed that Fiore's signal is coming from a location nearby, and decides to visit the location (Keima's house). Before entering the house Lune gets a message response signal from Fiore (in actuality the response was triggered by Ryō following Nora's instruction). Annoyed by this late response, Luna leave the premises, but not before carving an "X" and leaving her box cutter stuck in the front door of Keima's house.
Much later, as Lune was feeling pleasure from stabbing herself, Vintage calls her, telling her that she is the new District Chief in charge of the now-fired Haqua's area. Lune wishes to turn down the offer, but the vintage member tells her that she can't, as it is such an important time now. Lune asks for Haqua's log, which makes the vintage member puzzled why. Lune responds that something has been bothering her, meaning that she will take Haqua's place.
During the Eve of Mai-High festival, Lune manages to arrive and accidentally bumped into Ayumi. Ayumi says sorry before leaving. Lune (while holding a cup in her mouth), takes out her skull sensor and faces it towards Ayumi, but there is no response. Lune looks towards Ayumi while mumbling to herself.
Lune was later seen at the 2-B cafe ordering a cup of coffee with loads of sugar. Affter that, she is seen calling to another Vinatge member to gather as much troops as they can as she apparently had a plan to capture a goddess.
Later, she was shown to follow Ayumi and "tagged" her. Lune the ordered her surbodintaes to thier preparations and then begin the hunt. While finishing that, She bought some Takoyaki too.
By nightfall, Lune was lying on a bench and was thinking of the possibility that the goddesses may be disguised as the Runaway spirits. Later, a Vintage member said that the peperations are compeleted as Lune said that they will begin immediately as she said that they will find out who's having a goddess if they capture Keima's previous conquest targets(12 of them) all at once.