Elfen Lied

After killing many facility employees, Lucy escapes from the facility where she has been contained. However, a sniper shoots her in the head as she is escaping and she falls into the water. When she reaches the shore, she doesn't remember her past and can't even speak except for saying Nyu. At the shore, Kohta and Yuka find Lucy and try to help her. Since she doesn't seem to understand the language, Kohta and Yuka decide to bring her to Kohta's new residence and decide to call her Nyu. When Kohta shows a seashell to Yuka saying that it is his little sister's memento, Nyu breaks it since she didn't understand what he was saying. Kohta gets very upset and Nyu runs out of the house.

Police are combing the city trying to find Lucy. Kohta finds Nyu at the beach where Bandoh, a member of SAT, and his partner are looking for Lucy. When they find Nyu, they beat Kohta up and take her. Bandoh tries to provoke her because he wants to fight one on one. Since she is Nyu right now, she gets very scared and does nothing. So Bandoh gives up and tells his partner to kill her. That is when Nyu becomes Lucy.

Kurama asks Nana to find Lucy using her ability as a Diclonius and Nana accepts the request. Kohta catches a cold and Yuka, who came to drop off her clothes for Nyu, realizes something is wrong. She sits by Kohta helping him get better. While she is there, she notices that Kohta thinks that his father died in a car accident and her sister died of a disease, although they both (probably) were killed by Lucy in a train.

Nana fights against Lucy and is wounded. Lucy then changes back to Nyu and meets Yuka by accident. Before meeting Nyu, Yuka finds out that Mayu may be homeless. Kohta gets a call from the hospital saying that someone was injured and goes there to find Mayu and tells the hospital people that she is his relative and is in town for a visit. He takes her home where Yuka and Nyu are back and getting ready for dinner. Thinking Mayu probably hasn't eaten well, she suggests Mayu have dinner with them. She also suggests that Mayu should take a bath and stay the night with them.

Mayu stays over night with Kohta and Yukabut leaves them a note in the morning saying that she didn't want to be a burden to them. Kohta, Yuka and Nyu go looking for her. They tell the police officers that Mayu is their family. Kohta and Yuka decide to look after Mayu so they go see her mother to get permission. Kohta and Yuka take Nyu to their school and Professor Kakuzawa notices it is Lucy. He tells Kohta and Yuka that Lucy is his niece and he'll take her home.

With new, stronger hands, Bando searches for Lucy hoping to gain revenge. But, Lucy is still missing, because after killing Professor Kakuzawa, she runs away again. Kouta and Yuka set out to look for her, but cannot find her. Will they find Nyu? Or, will they find Lucy? If they do find the latter, will they be safe?

Nana's horns come out when Bandoh threatens her with a gun. When she realizes he's after Lucy, too, she suggests that they work together. He rejects the suggestion but tells her to contact him when she knows where Lucy is. Wandering about, Nana comes to the place where she once fought Lucy and runs into Mayu. Mayu faints when she sees Nana's leg come off and Nana tries to help her. When Mayu regains consciousness, Nana asks Mayu to be her friend. Mayu takes Nana home and when the door is opened, Nana finds Lucy in the house.

Knocked out by Nana, Nyu loses consciousness and Kohta slaps Nana for what she just did. Nana tries to tell them Lucy (Nyu) is a very bad person, but no one listens to her. Meanwhile, Lucy's personality surfaces. Director Kakuzawa had Arakawa bring his son's head to his office. There, he shoots Arakawa and tells her that he'll save her but she has to cooperate with him. Kakuzawa also tells Kurama that he needs to be loyal to his boss and that they are going to use #35 to dispose of Nana and capture Lucy.

Lucy dreams about her childhood. After killing people at the children's home due to her anger at the boys killing her dog friend, she started wandering about, killing families to stay in their homes. One day she met Kohta who told her that her horns looked very cool and asked her to be his friend. The next day, Lucy went to festival to find Kohta because she wanted to tell him how she felt and found him with a girl. Lucy became sad and angry and started killing people at the festival. After that she went to the station where Kohta and his family were about to leave.

When Nana sees Lucy, she tries to fight but Mayu interrupts them. When Mayu asks them to stop fighting, Lucy remembers young Kohta asking her to stop and returns back to Nyu. Kurama has a flashback about how he got infected by a virus that resulted in having a Diclonius daughter. In his flashback, he also remembers the day his wife died. When Kurama tried to kill his daughter, his wife walked in. In the current time, Director Kakuzawa gives an order to use #35 who is said to be a worse monster than Lucy.

Shirakawa releases #35 in spite of her colleague's opposition. Shirakawa threatens #35 / Mariko that unless she listens to her, she'll detonate the bomb that was planted in #35's body. In the meantime, Kurama leaves the research facility to talk to Bandoh. He makes a deal with Bandoh to get parts for Bandoh's damaged artificial hand and in return Bandoh kills #35. At Kaede House, Nana starts feeling happy and hopes that Nyu doesn't go back to Lucy so that they don't have to fight.

When #35 gets tired of playing and is about to kill Nana, Kohta runs into the scene. Nana tries to save Kohta and falls into the ocean. The research worker gives orders to kill both Nyu and Kohta, but Nyu comes back to Lucy and saves themselves by repelling the gun bullets with her vectors. Lucy starts killing the officers and the bloody scene makes Kohta recall the sealed memory of his sister and father's murder by Lucy from his childhood. There, Bandoh appears looking for #35 and finds Lucy. Since he's been looking to get revenge on her, he starts shooting at her.

Just when Nana falls into the ocean, Kurama arrives at the scene and saves her. #35 is taken to somewhere to be watched over. While she's in bed, she overhears that her father's name is Kurama. Kurama tells Nana that he'll have to kill #35 and they go find her. Lucy's also coming to find #35 to fight.