Go! Go! Loser Ranger! manga volume 1 features story and art by Negi Haruba, the creator of The Quintessential Quintuplets.

When the Monster Army invaded Earth thirteen years ago, the Divine Dragon Rangers rose up to stop them! With the war raging on, these great heroes are mankind’s last hope!

...or are they?

In truth, the invaders were subjugated within a year, forced to continue to crank out a monster a week for the Rangers to crush in front of their adoring fans! But one monster has had enough. Something has to change! He’ll rebel against the might of the Dragon Rangers and destroy them all...from the inside!

Go! Go! Loser Ranger! manga volume 2 features story and art by Negi Haruba, the creator of The Quintessential Quintuplets.

Thirteen years ago, the Nefarious Monster Army invaded Earth, but humanity’s great protectors, the Dragon Keepers, defeated them in a single year! Every Sunday since, the monsters have been forced to act out humiliating defeat after defeat in front of the unsuspecting public. Determined to change this, a single monster, D, infiltrated the Ranger Force. With the help of the mysterious Ranger, Yumeko Suzukiri, D managed to seize one of the divine artifacts—the only weapons capable of permanently killing the monsters’ immortal bodies! However, D’s subsequent encounter with the Dragon Keepers led to his unfortunate end, so who will stop them now...?

Go! Go! Loser Ranger! manga volume 3 features story and art by Negi Haruba, the creator of The Quintessential Quintuplets.

D, a monster, and Hibiki Sakurama, a Ranger, have found a mutual goal in ending the war…one way or another! Hibiki is determined to reform the Ranger Force from the outside, and D vows to crush it from the inside. To that end, he has once again infiltrated the Ranger Force by swapping places with Hibiki, but the real hardship is only beginning. If he wants a shot at the Dragon Keepers, D must first pass the Ranger training to move up the ranks. Yet, with the sudden visit of Hibiki’s sister and the discovery of a mysterious monster hiding in his closet, how will D manage to keep his identity hidden?

In the heart of the Ranger Force, discovery will mean certain death!

Go! Go! Loser Ranger! manga volume 4 features story and art by Negi Haruba, the creator of The Quintessential Quintuplets.

After having infiltrated the Ranger Force in the guise of trainee Hibiki Sakurama, D must pass the final exam for promotion into a real squadron, or he’ll never gain access to his true goal, the Dragon Keepers. However, the test seems impossible: the candidates must retrieve a key from their assigned examiner, but the examiners’ power is overwhelming! If they could work together, they might stand a chance, but they soon discover there’s only a single “key” per team, and quickly turn on each other! Meanwhile, deep in the shadows, a monster boss thought long destroyed is making a move… Will D be able to survive this battle royale?