"Bad-Ass Dude" is the seventh episode of the Durarara!! anime.
Shizuo Heiwajima states that he hates violence. He and Tom Tanaka are listening to a man's excuse for not paying up when Shizuo gets angry and throws a sign post at him. Tom complains they will never collect any money if Shizuo keeps beating up clients when they arrive at a vacant apartment. The resident has been missing for several days and the two decide it must be because of the human traffickers.
Tom and Shizuo are in a crowd in downtown Ikebukuro when Shizuo sees a flash of red - the eyes of the Slasher. He decides something strange is going on in the town. Simon Brezhnev greets him, but Shizuo ignores him and continues walking, and Tom explains Shizuo is acting a little like a rebel lately. Kyouhei Kadota also says hello, but Shizuo ignores him, too. After Shizuo stops under a poster advertising Yuuhei Hanejima's new movie, tabloid writer Shuuji Niekawa complements Yuuhei's looks and acting skills, then tells Shizuo he must be very proud to be Kasuka Heiwajima's older brother. This angers Shizuo, who throws him in the air.
In a flashback to Shizuo's childhood, he was angered by Kasuka eating his pudding and tried to throw a refrigerator at his little brother. However, he only succeeded in breaking his arm. Due to this, he was teased by his classmates in elementary school and threw a desk into the wall, once again injuring himself. In the hospital, a child Shinra Kishitani discussed his thoughts on Shizuo's abilities. According to him, while most people's strength is limited by their brains to prevents muscle and bone damage, Shizuo can always reach the limit of his adrenaline. Shinra asked if he could have a blood sample to examine. Shizuo grabbed his arm and accidentally broke it. Soon after, Shizuo decided that if he was going to destroy his body if he held back, he would stop holding back.
As Shizuo and Kasuka walked home, they met a kind shopkeeper who commented on Shizuo's tendency to get injured and gave them bottles of milk. Later, he saw men harassing the shopkeeper, lost control, and destroyed the shop, injuring her in the process. Sitting at a park with Kasuka, Shizuo asked if his little brother is ever scared of him, to which Kasuka replied, "not really."
In high school, Shizuo and Shinra discovered they were attending the same school once more. Celty Sturluson drove up and Shinra told her he was worried when she didn't come home. He asked if she was looking for her head, which she confirmed, but he joked with her, saying she was probably seeing another guy (to which Celty punched him). Shinra introduced Shizuo and Celty by announcing that he was going to marry her.
After destroying the Raira's soccer field, Shizuo met Izaya Orihara, Shinra's friend from middle school. Shizuo instantly dislike him and attempted to punch him, but Izaya responded by slashing Shizuo's chest with his knife. Izaya said their fight was indeed a blast. Shizuo proceeded to chase him through the streets of Ikebukuro, then was run over by a truck. Izaya paid the driver, who was shocked.
Shizuo arrived at Shinra's apartment and broke down his door while Celty tried to calm him down. Shinra was excited to see Shizuo although Izaya was at his place, too. Izaya was amazed Shizuo could still stand after their fight. In Shizuo's apartment, he ranted to Kasuka, who pulled out a bottle of milk for Shizuo to drink.
Gangs sent by Izaya would take on Shizuo to boost their reputation, although none succeeded in beating him. Shizuo commented that while Shinra and Celty were still the same as always, Izaya was hatching something with the Awakusu and yakuza. Shizuo wanted to settle down and tried multiple jobs. Kasuka, who was a famous film star by that time, visited the bar at which he was working and gave him several bartender uniforms, saying Shizuo should stay in one place for a little while.
Izaya framed Shizuo for a crime he didn't commit, but the police soon realized his innocence and released him. However, he was again fired from his job and apologized to a poster of Kasuka. Tom was passing by and asked Shizuo to be his bodyguard, assuring him he would never have to fight because people would pay up upon hearing Shizuo's name. They passed Kasuka preparing to shoot a movie, and while Shizuo avoided eye contact, his little brother saw him and nodded. This make Shizuo feel a little more at peace.
He and Tom were collecting money from three delinquents in an arcade. One of them asked if Shizuo was a butler, and Tom was shocked they could live in Ikebukuro and not know Shizuo Heiwajima. One of the delinquents spit his drink on Shizuo and asked "the butler" to get him another. Shizuo, angered by the destruction of the clothes his brother gave him, destroyed the entire arcade. He decided he would have to grow stronger so that someday he could control his anger.
In the present day, Shizuo tells Celty this story. She had come to check on him, but he assured her he was relieved now that he had told her. She comments that he really loves his brother, which Shizuo accepts with a smile. He passes Kyouhei and Simon again, this time acknowledging them, and decides that today is a great day. He spots Izaya watching him and begins yet another chase. Izaya runs away, leaving Shizuo to angrily yell his name.
Kanra announces that Shizuo has been going on a rampage lately. TarouTanaka asks if he is the guy who dresses like a bartender, but Kanra continues his story, saying Shizuo's always violent but has been going even more crazy lately. TarouTanaka admits to having seen Shizuo before and says he's scary, so Setton sticks up for Shizuo and tells the chatroom not to assume things they haven't seen for themselves. Kanra asks if Setton knows him, and when she denies it, he decides she might be in with the yakuza.
- To when the tabloid writer was asking questions on the street about the toughest guy in Ikebukuro in episode 5
- Many of the events in this episode are anime exclusive or alluded to later in the light novels.
- Haruya Shiki (partially seen)
- Shizuo Heiwajima
- Tom Tanaka
- Shuuji Niekawa
- Simon Brezhnev
- Kyouhei Kadota
- Kasuka Heiwajima
- Shinra Kishitani
- Celty Sturluson
- Izaya Orihara
- When Shuuji approaches Shizuo, the anime posters that can be seen alongside the promotion for Kasuka's new movie are of Le Portrait de Petit Cossette, Darker than Black: Gemini of the Meteor, Baccano!, and Cencoroll.
Simon: "Shizuo acting like he in puberty?"
Simon: "Shizuo, you finished going through puberty?"