Hiroko Takashiro is one of primary characters of the Bible Black Series and has been in all three series and the Bible Black Only side story.
Once upon a time Hiroko Takashima was a young high school student that dabbled in witchcraft with several of her classmates, Morita Rie and Shidou Saki. One day the trio came across the book that would be referred to as the BIble Black. The book was acquired for a tiny percent of its value and found in a common bookstore. The girls began practicing magic and would eventually charge money for casting love spells for various students. After they were denied club status Takashiro and her friends cast a lust spell on Junko Mochida. The young girl strips during an assembly and masterbates before the student body.
After casting a love spell on Nami Kozono, the group begins to make serious money once the word gets out. Eventually the group tries summoning a demon and Hiroko is raped by the conjured beast. Nami takes control of the group and plans to use virgin Reika Kitami as their sacrifice. Hiroko does not take part in the ceremony as she was deemed to weak and locked in a closet. She saw the aftermath of the blood bath but kept her involvement in the group a secret from the administration. She was unaware of Kitami's role as the sacrifice and her pact with the devil.
Many years later Hiroko is now an art teacher at the school she once attended. She is completely unaware that Reika Kitami, is searching for a virgin to exchange souls with. After Kitami seduces Taki Minase, Hiroko is subduded and sexually abused by the current Witchcraft Club. She succeeds in releasing Minase from his demon but not before she reveals to Kitami that she was (inadvertently involved) in the ceremony that she was the sacrifice for. Also she is not able to help Imari who will be the new virgin sacrifice to prolong Kitami's life.
Hiroko, with Minase's help, manages to escape the coven and the two take shelter at Minase's home. Minase shows Hiroko the Bible Black, and the two try to find a way to stop Kitami from carrying out her plan. Minase returns to Saki's apartment in a vain attempt to save Imari but is unsuccessful. Kitami gives him the Bible Black as she has no further use for it and believes that it has nothing that can harm her. Upon returning to his home Hiroko informs Minase that she has found a spell (two pages were stuck together by blood) that can stop Kitami. As she explains her plan the drugs that Hiroko was give by Kitami begin affecting her and to keep from going insane she and Minase make love, once in the evening and again the following day. Unknown to the pair the later is observed by Reika Shiraki.
Shiraki later stabs Minase in a jealous rage and as the two make love (while Minase bleeds out), Hiroko stuns Shiraki and undoes the magical influence on her. Hiroko and Minase then depart for the school to stop the ceremony.
Hiroko personally battles Kaori Saeki, who has replaced Minase as Kitami's partner. She gives Minase the spiritual aid he needs to complete the spell to stop Kitami from completely swapping souls with Imari. Hiroko then uses her magic to erase the memory of the events from the student body and Minase's sister.
At some point in time before the events of Bible Black The New Testament, Miss Takashiro discovered that Miss Kitami has transferred part of her soul into Imari's body. She then bound the soul so it could not influence Imari.
Also in the years that followed Minase and Hiroko renewed their sexual relationship.
Hiroko appearance alters more noticeably than the rest of the characters throughout the seasons. Hiroko hair style changes three times within the main story arches to co-inside with her age and chest size and is almost never without her stocking.
Due to the unknown time laps between La Noche de Walpurgis (the original series) and La Lanza de Longinus (Bible Black: New Testament) it’s not possible to say how old Hiroko currently is. At the time of Bible Black Origins however it can be assumed that she is 18 years old (because it's illegal to depict anyone under the age of 18 naked) being a senior in high school. By the time of Bible Black: La Noche de Walpurgis twelve years have passed and they have done nothing but add to Hiroko figure now aged 30-31. Bible Black Only takes place around the time of Bible Black: La Noche de Walpurgis but no indecisions to when they occur either before or after La Noche de Walpurgis are never given. Due to the time it takes to become an art teacher, Hiroko could be between the ages of 22 - 32 at this point. Bible Black: New Testament takes place some years later by this point Hiroko is likely to be 36-38 years old due to the time its taken Kaori Saeki to become a teacher at the school. At any age Hiroko remains a priceless beauty with lushus red hair, kind purple eyes, a tall and average figure with big natrual
breast To-date Hiroko can be seen wearing ten outfits though the progression of Bible Black (Listed as first seen on the timeline): School Uniform, Home Clothes, Magic Rode, Teaching Clothes, Underwear, PVC Clothing (game only), Full Body Lingerie, Nuns Attire 1 & 2, Ninja Dress.