A Nótt Dvergur, Níls is a short young guy. Contrary to Dóra, Níls has white skin and light-colored hair (it's unknown why this the case or why he isn't classified as a regular Dvergur). He is shown wearing a sleeveless dogi.
Like Bjarki and Kató, his partners in crime, Níls is a lecherous boy who will do anything to catch a glimpse at the beautiful naked body of a girl. Contrary to the other two, he has ninjutsu skills and is far more competent at peeping at girls, although, normally, the luck is against him and ends up failing at the last moment due to unforeseen and ridiculous circumstances.
While his profile says he is a Nótt Dvergur, he looks like a normal Dvergur. Furthermore, even though his roots are from the Northern Dvergur country (Lukka's Kingdom), he was born in Ygvarland. Some time after classes had already started in the Royal College, Níls returns from his training with a ninja from the East, having successfully mastered the Wind Manipulation Technique that he learned in order to be able to blow the wind and trigger a lucky event (blowing the skirt up of beautiful girls). As members of the Celestial Bodies Research Club, he meets with Bjarki and Kató to try to confirm the veracity of one of the school's seven legends: the existence of the legendary secret club "Front for the Liberation from Restraints". In order to do that, Níls would use his Wind Manipulation Technique to find a girl that's not wearing underwear. They successfully implement their plan with Lukka, Yuna and Rotte. After doing that, none of them is going commando and Níls has almost already expended all of his energy. With only one more shot, they plan to use the technique once more in a way to affect the remaining girls (Míst, Asuha and a forced to crossdress Naoya). Their attempt is successful and they manage to locate a member of the Front (unbeknownst to them, two of them), but, at the same, by flipping Naoya's skirt, they enter in shock and collapse since, by coincidence, that day Naoya was not wearing underwear due to a washing mistake by Críe, so they get a full view of his package.
When Enja calls Rotte, Elíka and Míst to her house inside the school in order to serve as models for the selection of new uniforms, Níls, Bjarki and Kató go there as well in order to be able to peek at them. They are confronted by Sigurð, who happened to see them. After explaining their plan, Sigurð joins them. Níls had prepared beforehand a storage shed along the wall from behind a one-way mirror in order to peep at will. When they are about to see Míst without panties, Sigurð and Dóra choke Bjarki and Kató out as the prince felt peeping unsatisfying after seeing Rotte inside. Níls, however, manages to escape and, using a ninja stealth technique (hanging on the ceiling while hiding in a wallpaper-like cloth) he arrives to the rooms where Nana is about to take the photographs of the girls in the new uniforms. Naba, however, is as lascivious as Níls, and, through sweet-talking Rotte, Elíka and Mist, she manages to make them pose in titillating fashion. In her final attempt, she convinces them to kiss between them. As they are about to do it, Nana gets so excited that she jumps at them trying to join them. At the same time, Níls, who was overjoyed to be able to see this unexpected situation, slips from his grip and falls down, making him hit head-to-head with the jumping Nana, knocking them both out and awaking the girls from the spell in which they were engrossed without noticing.
At the time Rotte and her group travel to the Northern Dvergur country, Níls, Bjarki and Kató are also trying to get there to peep at girls using the famous hot springs of the region. In particular, they are looking to find the legendary Celestial Maidens' River, a river in which beautiful women bath. Coincidentally, Rotte and her group find the Celestial Maidens' River and decide to bath there. Naoya, who is put in charge of guarding the clothes of the girls, goes to the toilet for a few moments and returns to find the clothes missing and Níls, Bjarki and Kató knocked out. It turns out that the three of them stumbled upon the clothes that Naoya left unguarded while he went to the toilet and tried to steal the clothes, but a monkey took them first as they were jumping at the clothes, causing them to collide heads and get knocked out. When Níls is waking up, Yuna knocks him out again thinking him a pervert since Naoya left him in his underwear while trying to locate the girls's clothes.
Some time before Rotte and company went to Effie's hometown, Níls, Bjarki and Kató tried unsuccessfully to enter but were arrested by the guards of the village.