Takuma Hasumi

Takuma Hasumi (蓮見 琢馬) is an antagonist featured in the The Book: 4th Another Day novel, based on Diamond Is Unbreakable.

Appearance/Personality
Takuma is a teenage male with a slender build and a horse-shaped birthmark on his neck. He has the natural ability to memorize everything he sees, hears or senses at all times, including the smallest details. Forced to remember things he wants to forget, such as the pain of getting hit by a car, Takuma has produced permanent red marks on his arms from scratching them so hard. He had no control over his memories until he developed his Stand, The Book.

To hide his arms, Takuma only uses long-sleeved jackets and refuses to take them off. He is also always seen with a pen, given to him by the Crybaby Boy, his friend in the orphenage. Takuma has chosen to live a reclusive life, in order to avoid collecting more data. He is usually described as being "a void without emotions". However, it is revealed from the past story of Takuma's friendship with Crybaby that Takuma is deep down kind and considerate. This can also be proofed by Takuma saving Chiho from a deliquent when he was 13, unaware of Chiho is Teruhiko's daughter.

History
Takuma is the son of Akari Hirai and Teruhiko Okami. When his mother died after giving birth to him, his father abandoned him in a temple. Takuma was then taken to an orphanage and got this name by the orphenage dean inspired by his horse-shaped birthmark. The orphanage staff found out about his ability to not forget anything and thought he was a genius, but were disappointed when they realized he could only store data, but not actually put them together to solve problems.

His ability made his life much worse, as he could never forget anything in his head. Takuma tried suicide multiple times, but never succeeded. He eventually developed his Stand, The Book, and so the memories once stored in his head were stored in the Stand, so he could remember anything in his life anytime he wanted just by looking at it.

During his elementary school life, by reading the distant past of himself from The Book, Takuma found out that his mother died oppressed by Teruhiko and vows revenge. After moving into a house where a suicide case happened before, Takuma started to practise throwing knifes. With the help of The Book, he soon mastered this skill no matter what kinds of knives he used. When Takuma was 13, on a winter night, he encountered the 12-year-old Chiho Futaba, getting entangled by a deliquent on her way of home leaving. Takuma then used a knife to cut down one of the deliquent's ears, saved Chiho and left. From then on, Takuma continued his reclusive life, remaining unfamiliar to anyone.

It is revealed later in the story that Takuma still keeps contact with the orphenage and occasionally goes there to help the work, probably implying Takuma's living is supported by the orphenage.

The Book: 4th Another Day
Takuma kills his father's former lover Hanae Orikasa with his Stand so he would come in contact. He then meets Chiho at Thorn Parlour, a local library Takuma likes to go, and develops a friendship with her, who is unaware that she's actually Takuma's half-sister. Believing it to be the work of a Stand user, Rohan Kishibe and Koichi Hirose start an investigation on the death of Hanae, which is later accidentally known by Takuma. When Takuma passes by Koichi along with Josuke Higashikata and Okuyasu Nijimura in the school, Okuyasu unintentionally steps on his pen and breaks it, which is received from Crybaby as a gift when Crybaby gets adopted and leaves. Josuke then uses Crazy Diamond to repair the pen, being seen by Takuma's eyes and causing Takuma's vigilance to them.

When Takuma secretly observes Josuke and his fellows, he realizes they are in pursuit of a student with scratch on the arms. To confuse them, Takuma uses The Book to implant his memory of strongly scratching his arms to multiple male students in the high school, causing the actual damage on their arms. At a day when Takuma is walking with Chiho, he is stopped by Josuke sitting near a pool in front of the train station, for asking time. When Takuma is watching on his watch, Josuke uses Crazy Diamond to loosen the watchband with a pin and make it drop into the pool, forcing Takuma to pick it up with his sleeve rolled up so that he can check Takuma's arms. Understanding Josuke's intention, Takuma picks up his watch without rolling up his sleeve, causing Josuke's suspection. The small interogation ends up with Okuyasu running to Josuke and telling him the discovery of several students with scratch on their arms.

Regarding the investigation of Josuke and his fellows as an obstruct, Takuma decides to kill Josuke. He tears down one page from the forbidden area of The Book, recording his painful memories during his childhood, such as suicide commitment, car crash (which is the one Takuma used to kill Hanae Orisaka), and influenza. Planning to use the page recording his wrist-cutting suicide memory to kill Josuke, he seals the page in an envelope and directly sends the letter to Josuke's home. However, Takuma's plan unexpectedly fails because Josuke's mother, Tomoko Higashikata is the one checking the letter and reading the page. Though Tomoko's life is safe thanks to Josuke's immidiate rescue, what Takuma's done has seized Josuke's attention and made his mind to catch the culprit.

As time goes by, Takuma and Chiho start a relationship, based on Chiho's growing affection to Takuma and her discovery of the truth that Takuma is actually the teenager who saved her from a deliquent with a knife during her home-leaving. Later, Takuma is invited to Chiho's home for dinner, getting the chance to confront his father, Teruhiko Futaba. Though surprised at finding out Teruhiko can also see The Book, Takuma manages to show his tracking research of Teruhiko's social circle, Teruhiko's illegal commitments, and his idea of marrying Chiho to Teruhiko, making him panic. After that, on the way of Chiho sending Takuma off, she receives a black amber necklace from Takuma, which is the one Teruhiko gave Akari, and Takuma gained from the building gap while searching for Akari's corpse. The necklace gives the final hint about Takuma's indentity to Teruhiko, arising an enormous despair to Teruhiko. Right at this point, Takuma's revenge is considered as completed, for his true purpose is not killing Teruhiko, but making Teruhiko live the rest of his life in deep regret.

Takuma plans to leave Morioh Town, for he has achieved his goal here. Before he sets off, he wants to finish Chiho's manuscript at Thorn Parlour. However, Okuyasu finds Takuma and tries defeating him. Even though Takuma manages to defeat Okuyasu using his influenza memory, he is later chased by Josuke to the roof. During their fight, Takuma is being overpowered. Takuma finds out that Josuke was saved by an student with a pompadour in his past and tries to use it against him, but this just upsets Josuke more. While Takuma is able to heavily injure Josuke, he is eventually defeated by him, ending up falling from the building to his own death wish. After this happens, the orphenage claims Takuma's body from the police and holds his funeral at the temple where he was initially found.