Lagoon Engine

is a manga by Yukiru Sugisaki. It has been suggested that this series is a sort of prequel to the manga series Lagoon Engine Einsatz, but no statement has been made by the author or publishers to support this idea.

The two main protagonists of the manga are named Yen and Jin. Their surname is Ragun. When put in a certain order (Ragun Yen Jin) it sounds like 'Lagoon Engine'.

Trivia --- Yen and Jin once appeared in D.N. Angel as cameo in both manga and anime. In manga volume 9 there is a page where both en and jin is carrying theirs Kakuki and anime, they appeared in episode 10 wearing a suit.

Plot
Lagoon Engine revolves around two main characters: 12 year old Yen Ragun, and his little 11 year old brother - Jin Ragun. While Yen Ragun is intelligent, calm, and thinks tactically, Jin is hotheaded and rushes into battle.

The Ragun family is dedicated to defeating ghosts, evil spirits, etc. - all 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. On the other hand, Sora has NO intellectual power whatsoever, but his attack power is painstakingly high.

How Gakushi-Maga 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 basically get tasks from their father to complete which usually involve fighting maga.

Kamen Kugutsushi The enemy of the gakushi. Gakushi cause maga to calm down to become their allies instead of causing chaos and destruction. The Kamen Kugutsushi are just the opposite. They stir up the maga, causing them to become angry and cause uproar. They have 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?