G Senjō no Maō (G線上の魔王, officially translated into English as The Devil on G-string) is a Japanese adult visual novel developed by Akabeisoft2 and first released for the PC as a DVD on May 29, 2008 in limited and regular editions after many delays.[ The ]gameplay in G Senjō no Maō follows a plotline which offers pre-determined scenarios with courses of interaction, and focuses on the appeal of the four female main characters. The title G Senjō no Maō comes from August Wilhelmj's "Air on the G String", an adaptation of J.S. Bach's original "Air", and Franz Schubert's "Der Erlkönig" known as Maō in Japan.
Much of the gameplay in G Senjō no Maō requires little interaction from the player as the majority of the time is spent reading the text that appears on the game's screen. The text being displayed represents the thoughts of the characters or the dialogue between them. The player is occasionally presented with choices to determine the direction of the game. Depending on what is chosen, the plot may progress in a specific direction. There are four different routes in total.
The player assumes the role of Kyōsuke Azai (浅井京介 Azai Kyōsuke ), the protagonist of G Senjō no Maō. Kyōsuke is the adopted son of a yakuza leader. Though during the daytime, he puts up a kind, sociable air around him, he is in fact a highly intelligent and ruthless businessman and the president of one of his father's, Gonzō Azai's, corporations, where he works in order to pay off a massive debt he owes to his adoptive father. Due to his "education" under Gonzō, Kyōsuke views money as the only important thing in the world and does anything he can to gather more and more of it in order to pay off his debt. Kyōsuke is a big fan of classical music. Haru Usami (宇佐美ハル Usami Haru , voiced by: Rino Kawashima) is the main heroine of G Senjō no Maō. She has long black hair and is extremely intelligent. Haru has a long history with Maō but is hesitant to tell anyone about it. Maō (魔王, voiced by: Hōdenirappa) is the primary antagonist of the game. Maō's background is shrouded in secrecy and little is known about him. Eiichi Aiazawa (相沢栄一 Aizawa Eiichi , voiced by: Mahiru Kaneda) is a close friend Kyōsuke's. Eiichi harbors a (comedic) dark side beneath his cute facade and is into older women.
Tsubaki Miwa (三輪椿姫 Miwa Tsubaki , voiced by: Sumire Murasakibana) is a classmate of Kyōsuke's. She likes writing in her diary. Kanon Azai (浅井花音 Azai Kanon , voiced by: Haruk Kawai) is the daughter of Kyōsuke's adopted father. She is a professional figure skater. Mizuha Shiratori (白鳥水羽 Shiratori Mizuha , voiced by: Erena Kaibara) is another classmate of Kyōsuke's and is the daughter of the director of the school. She is very cold towards Kyōsuke. Yuki Tokita (時田ユキ Tokita Yuki , voiced by: Hokuto Minami) is a close friend of Haru's. Yuki has studied criminals for a long time and is skilled in negotiations.
G Senjō no Maō's story revolves around Kyōsuke Azai, the adopted son of Gonzō Azai (浅井権三 Gonzō Azai ), a yakuza leader. Kyōsuke works under Gonzō in the hopes of raising and returning the debt that his father owes the yakuza and for the sake of his sick mother. One day, a girl named Haru Usami transfers into Kyōsuke's school who declares herself to be a "hero" and asks if Kyōsuke knows someone named Maō. Kyōsuke says that he does not, but later that evening, receives a letter from "Maō". Gonzō instructs him to find and capture Maō.
Throughout the story, Maō engages Haru in a variety of ways by threatening those around her. The first incident involves Tsubaki where her brother is kidnapped with Maō asking for an exorbitant sum that can only be paid if Tsubaki's family sells their land and moves. Kyōsuke helps Tsubaki obtain the necessary funds as he himself is interested in getting Tsubaki to move due to him having an investment in the company that wants to get the Miwa family off their land.
In the second incident, a threat is sent to Gonzō that asks Kanon to purposely throw away her chance at the Olympics so that another skater can represent Japan instead. The threat turns out to be a diversion as Maō's actual target was Gonzō. Gonzō had considered this possibility and he evades being killed by the bomb that Maō placed under his vehicle. The third incident involves Yuki Tokita trying to extort money out of Mizuha Shiratori's father. Yuki is actually Mizuha's half-sister but she and her mother was driven out of the household which drives Yuki to want to exact revenge on Mizuha's father. Kyōsuke and Haru manage to outwit Yuki. Kyōsuke had rashly asked for help from the yakuza which gets him in a lot of trouble with Gonzō for daring to order his men around.
Maō is revealed to be Kyōsuke's brother, Kyōhei. Kyōhei hates Haru and Gonzō because Haru's parents are the ones that drove his father into debt and to commit murder and because Gonzō's loan sharks drove his father into such a helpless situation. Kyōhei initiates an elaborate scheme that drives most of the city into chaos. He demands the release of several criminals including his father and while most of the criminals he asked to be released were ignored, his father was on the pardon list and he agrees to the conditions and pulls his men out.
Kyōhei is able to evade capture at the end of the incident and pays Kyōsuke and Haru a visit later. After a struggle between him and Haru, he escapes from the apartment with Haru giving chase and ultimately murdering Kyōhei. The two brothers talk for one last time before Kyōhei dies from his bullet wound. Haru's memories of the incident are slightly clouded and during the police interrogation, Kyōsuke tricks the cops into believing that he was the one that killed Kyōhei and spares Haru from a criminal conviction. Eight years later, Kyōsuke reunites with Haru and his daughter.
G Senjō no Maō is Akabeisoft2's ninth game in three years, and the second of four games released in 2008 alone. The project is notable as having very few people credited for having taken a part in the creation of the game. Planning for the project and the scenario were headed by Loose Boy. Art direction and character design were done by Alpha. The music in the game was composed by Tiko-μ, and entirely features arrangements of classical music.
Before G Senjō no Maō's initial release, two free game demos became available for download at Akabeisoft2's official website. In the demos, the player is introduced to the main characters in the game that is typical of the gameplay found in a visual novel which includes times during gameplay where the player is given several choices to make in order to further the plot in a specific direction. The full game was first released on May 29, 2008 in limited and regular editions playable as a DVD on a Microsoft Windows PC. The limited edition contained an art collection from Akabeisoft2's previous titles Sharin no Kuni, Himawari no Shōjo, that game's fan disc Sharin no Kuni, Yūkyū no Shōnenshōjo, and Sono Yokogao o Mitsumeteshimau: A Profile Kanzenban, a desk calendar, and a demo of Tayutama: Kiss on my Deity from Akabeisoft2's sister brand Lump of Sugar released two months after G Senjō no Maō.
Two drama CDs set in the G Senjō no Maō universe were released in 2009, the first on January 9 and the second on June 26.. Fourteen episodes of an Internet radio show to promote the drama CDs titled G Senjō no Maō Presents Haru to Eiichi no Haru Ichi Bang×2 (G線上の魔王PRESENTS ハルと栄一のハル★イチBANG×2) was distributed on the visual novel's official website between November 7, 2008 and May 8, 2009. The show was hosted by Rino Kawashima and Mahiru Kaneda, the voices of Haru and Eiichi in the visual novel, respectively. The show also featured four other voice actors from the game and drama CDs as guests: Sumire Murasakibana (voice of Tsubaki), Hokuto Minami (voice of Yuki), Satoshi Tsuruoka (voice of Ryūhei Oda (drama CD-only character)), and Jun Fukuyama (voice of Kyōsuke in the drama CDs).
Ichijinsha released a manga anthology titled G Senjō no Maō Comic Anthology on September 25, 2008 under their DNA Media Comics imprint. Ichijinsha also released a fan book titled G Senjō no Maō Visual Fan Book on July 14, 2009.
Most of the game's soundtrack is made up of remixed classical music. The visual novel has three main theme songs, one opening theme, one insert song played near the end of the game, and one ending theme. The opening theme, "Answer", is sung by Rekka Katakiri, written by Kanoko, and composed by Junpei Fujita. The insert song, "Close Your Eyes", is sung by Ayane, and is written and composed by Chiyomaru Shikura. The ending song, "Yuki no Hane, Toki no Kaze" (雪の羽 時の風), is performed by Barbarian On The Grove featuring Chata and is written and arranged by Bassy. The two theme songs were included on the compilation album The Best Game Vocals of Akabeisoft2 released on February 23, 2007 featuring theme songs from several games by Akabeisoft2. The game's original soundtrack was released by 5pb. on April 24, 2009 in a three-disc set.
From mid-March to mid-April 2008, about two months before G Senjō no Maō's release, the game ranked second in national PC game pre-orders in Japan. The limited edition of G Senjō no Maō ranked second in terms of national sales of PC games in Japan in May 2008, and the regular edition ranked twenty-sixth for the same month. The limited edition ranked again for June 2008 at twenty-third highest selling in Japan. G Senjō no Maō ranked first for the month of May 2008 in terms of sales at Getchu.com. The game ranked again at sixteen the following month in the same ranking. For the first half of 2008, G Senjō no Maō ranked third best in sales at Getchu.com. The game received first prize at the Bishōjo Game Awards for 2008.