Isolated Island Oni is an enemy shinkaisei-kan found in Kantai Collection. She was the boss of the fifth event map during the Spring 2014 event.
She is depicted with very long black hair, glowing red eyes, small breasts, two horns, a bonnet, and a frilled gothic lolita dress with detached sleeves. She also wears bodystocking and has two spikes protruding from her upper back like Airfield Hime.
She's often portrayed as a hikikomori in fanart (Isolated Island Oni). Her nickname amongst fans is "Ritou" (りとう) which is taken from the first two kanji in her name. Also, before Northern Ocean Hime was introduced, she was the youngest looking shinkaisei-kan, looking more like a 14-15 year old in comparison to the rest of the abyssal fleet whom look 18 and older. In fact because of this she originally had the Pixiv tag "敵艦隊のチャイドル (Teki kantai no chaidoru, lit. "Enemy fleet's child idol") before it was nearly taken over by Northern Ocean Hime.
She is based on Wake Island and is voiced by Ogura Yui.