The main protagonists are Yen and Jin Ragun. The name "Lagoon Engine" is derived from the phonetic pronunciation of the main characters' names (Ragun Yen Jin)
Volume 6 was released on December 1, 2009. Volume 7 was released in Japan only on the same day. Volume 7 is going to be released in September 2010 in the US.
Trivia --- Yen and Jin once appeared in D.N. Angel in cameos in the manga and anime. In Volume 9 there is a page where Yen and Jin are carrying their Gakuki and in the anime, they appeared in Episode 10 wearing suits.
Lagoon Engine revolves around two characters: 12 year old Yen, and 11 year old Jin. While Yen's intelligent, calm, and thinks tactically, Jin's hotheaded and rushes into battle.
The Ragun family is dedicated to defeating ghosts, evil spirits, etc. - known as 'Maga' Yen and Jin just happen to the successors of the family, and they have to fight Maga too. In short: Yen and Jin are Gakushi.
Both Yen and Jin have Maga - though not evil maga. Yen's Maga is called Koga, while Jin's maga is named Sora. Koga is good with gathering information, analyzing and remembering things, though he's extremely bad at attacking. Sora has no intellectual power whatsoever, but his attack power is very high.
How battles work When Gakushi fight maga, they must create a barrier. Within the barrier, the two opposing beings cannot see each other, and they don't know each other's names. When they guess the opponent's name correctly, they can clearly 'see' the maga. Their attack power will be at 100 percent, and the other side's attacks are ineffective. This is what yuusei is.
As a result, each side must keep their names from the other as much as possible.
Gakushi have their own names too - not names that their parents gave to them, but their own names. They never give any clues about their names. This is called an Omi name. No one but themselves know their omi name.
Yen and Jin get tasks from their father to complete which usually involve fighting maga.
Kamen Kugutsushi The enemy. Gakushi cause maga to calm down to become allies instead of causing chaos and destruction. The Kamen Kugutsushi are the total opposite. They rile the maga up, causing them to become angry and cause uproar. They've stolen nineteen of the books that maga have been sealed in. So far in the series, one has been destroyed, so there are eighteen left. Will Yen and Jin find them?
- Yen Ragun (等軍焔?)
- Intelligent, and good with making inferences, as is Koga. A good gakushi and often teams up with Jin while fighting maga. As a perception type, he can understand Maga. As shown in the second book, he hates slimy things, so he hates natto (fermented soybeans).
- Jin Ragun (等軍陣?)
- Yen's younger brother. Almost the complete opposite. Hotheaded and rash - seemingly not very bright either. However, he's still loyal to his brother, and loves him very much. He's never quiet and hates peppers.
- Ayato Housui (峰水綾人?)
- Ayato is related to Yen and Jin. Apparently, he's their cousin. He knows of Yen and Jin being Gakushi, and isn't bothered by it at all. He's quiet and polite. His nickname is "Aya".
- Miki Kirishima
- Miki is a girl in Yen's class who has not attended school for two years because of a deadly disease that confines her to a hospital. Her dead dog, Tom, was lead back to her by Yen and Jin, and is slowly becoming a maga. Yen thinks she'll become a Gakushi.
- Erei Moribayashi
- A friend of the Raguns. Loud, and rather hotheaded. She doesn't seem to know of the Raguns being Gakushi. She's taken a liking to Ayato.
- Shintaro Nagasaku
- 28, single, and works as an editor for Yen and Jin's mother. He seems to live at the household, and is rather strange. In fact, he likes to wear skirts.
- Akane Ragun (Mari)
- Akane is a very popular author. Her works never meet the deadline, but the books still end up being ridiculously popular. Although her true name is 'Akane Ragun', her penname is 'Akane Mari'. She's the mother of Yen and Jin.
- Hideaki Ragun
- Hideaki is the husband of Akane Mari and the father of the Raguns. He's a very experienced Gakushi, and extremely powerful.
- Suguru Mikami
- Suguru is a gakushi of the Mikami. The Mikami is a 'branch' of the Ragun. He appears to be the silent type at first - strong, cool and collective - but that's not all that there is to him. He hates being called "Branch Family" and Jin for calling him that. Besides that, it's very possible for Suguru to be nerve-wracked.
- Koga (Maga)
- Yen's maga companion. Koga cares for Yen very much, and reflects on Yen: Koga is intelligent, and makes a good team with Sora - Jin's maga. However, Koga lacks in attacking.
- Sora (Maga)
- Jin's maga, and also seems to have as much energy as Jin. Sora has no intellectual power whatsoever, but his attack power is very high.
- Shinno Zai
- Shinno is assumed to be a Kamen Kugutsushi, which is the enemy of the Gakushi. He attends the same school as Ayato, but Ayato has no idea that Shinno's Yen and Jin's enemy. Not much is known about Shinno.
- Hodou is Shinno's servant. He calls him master and does his bidding. He attends the same school as Ayato as well. Not much is known about Hodou, either.
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