A girl at Jun's school who is part of the swimming club, that developed the Devil Beast Syndrome and could turn into a demon octopus. She was disgusted of her appearance and jealous of Juns beautiful form that she wanted to reveal her true appearance to the school.
Youko Suzuki is one of the members of the school's swim team who developed the Devil Beast Syndrome sometime during the story. She became hateful of her monstrous apperance and became jealous of Jun Fudo, especially after seeing she still remained beatiful as she transformed.
Youko Suzuki was created by Go Nagai. It is unknown what inspired him to create her.
As Jun was getting ready to quit being a teacher Youko visited her and asked her to come and watch her swim. After school was over Jun came to the pool and was shocked to see Youko naked sitting in a chair waiting for her. Youko then told her to take a good look at all of her. Jun just stood in shock as Youko continued to fondle her body saying that she wanted her to watch her as she remained beautiful, saying she won't be a beautiful girl anymore and hating her for being able to stay beautfiul. Jun then realizes Youko has became a Devil Beast. Then all of a sudden Mr. Nejima and a bunch of students come in and start walking towards Youko in a daze. Jun tries to stop them but they just push her aside and began crowding on Youko and begin fondling and kissing her. Youko then begins to transform and bites Mr. Nejima with her new mouth located on her stomach. Soon her arms turn into tentacles and she tells Jun "watch as my beautiful body becomes hideous!" Jun then begins to transform and feels remorse she wasn't able to realize one of her students have transformed. Youko was shocked and excited to see her teacher turn into a monster like her, that she wanted to fight her. But Jun told her she is not like her and that she is a devilman and rams Youko into the pool.
As they fight Youko reveals her breast have become eyes and uses thier hypnosis powers to mind rape Jun by having her students see her naked and transformed. Soon Jun passes out and begins floating towards the surface. Youko then grabs her and realizes she should reveal Ms. Jun's true form to the student body the next day at her going away ceremony. Youko then makes her forget what happened and sends her away. The mind controlled Jun begins walking home but snaps out of her trance and is confused as to what happened. As she is trying to backtrack what happens, her friend Satomi arrives asking how her student was swimming but didn't know what she was talking about until she revealed her hair was still wet. Jun then decided to go back into the school and investigate. She then finds pieces of her swimsuit on the floor and in the garbage and realizes what happened but still has no recollection as to who she met. As she digs further in the garbage she finds a pair of panties and brings them to the H.A headquarters for examination. They reveal the panties were covered in mucus from some marine creature like a octopus or squid.
Meanwhile Youko was at her home in the bath as her body continued to transform this time her legs have split into more tentacles. Not to happy with what has happened she continues to think of what she will do to Jun the next day. As the next day came Youko encountered Jun at the main gates to the school and was talking to her. As Jun's gave her speach at her ceremony Youko shouted "Ms. Jun Please dont quit!" and then clapped her hands letting the post hypnotic command begin. As Jun began to transform an explosion hit the gym causing everyone to leave except for Youko and Jun. Jun then remebered that Youko was a devil beast and said her power was truly terrifying and that human society cannot tolerate her existence and that she will end that miserable form of hers. Youko then begins to fully transform not caring what Jun said saying "a monster should not act so self-righteous". As she finshed changing she began charging at Jun. Youko proves to be to fast in her new form and continues to mess with her by saying "turn into a hideous monster and I will spare you". But Jun just grabs one of her tentacles and throws her into a wall. Youko then begins to use her hypnosis on her again but Jun evades in time. Soon a group of H.A troops storm the Gym firing at Youko but she intentionally jumps in front of them and uses her hypnosis. At her command she orders them to fire on Jun. As Jun escapes and has time to expel the bullets from her body Youko sneaks up on her and grabs her until another H.A. soldier came from behind and shot her. Youko escapes but uses her powers to make a helicopter crash into the school. Jun then grabs her, throws her to the ground and rips all eight or her tentacles off and lets the H.A. soldiers rain bullets on her. With nothing left of her body but only chunks of meat Jun feels remorse towards her former student.
Youko Suzuki's main abilities were swimming and her beauty but when she transformed she became a demon octcpus with a pair of eyes on her breast and a second month on her stomach. When she first transformed she retained her legs but after fighting Jun the first time she discovers they have split into tentacles like her arms. Then finally her final fight with Jun she fully transformed leaving no traces of her human form. In this form Youko is incredible agile capable of using all eight of her appendages to move at incredible speed. With the eyes on her breast she is capable of using hypnosis to which she can control others or plant post hypnotic suggestions for her puppet to do later.