Haiyu Yamaguchi

## Arsino Mester

**Enji Matsuda** is an Actor-Type Humagear that was hacked by Herobe and given a Zetsumerisekey to transform into the **Arsino Magia**. Later, he was hacked by Hiroto Hayashi and turned into the Arsino Mester again during the Workplace Competition.

## History

Haiyu was introduced as the newly developed actor Humagear in the purpose to restore the image of Suzuki Intelligence from being marked as the creator of Humagear killer and their belief that Humagear is humanity's dream by producing a movie with the collaboration with Shin Kawasaki. During the film shooting, Haiyu performed perfectly as the script but still disappointed Kawasaki as he often ad-libbed the story. This enraged Hacker Assassin when he infiltrated the scene and attacked him. Although this discouraged Haiyu, Herobe hacked the actor Humagear into the Arsino Mester. The Arsino Mester and was completely destroyed by Valkyrie Lightning Hornet's Thunder Lightning Blast Fever.

After his destruction as the Arsino Mester, a replacement model resembling Haiyu was created and made the filming a success. Haiyu continued to improve from his acting from scratch, which did impress Kawasaki. Unfortunately, the filming went awry due to Hacker Assassin shooting and injuring Shin from a blind spot.

During the mock wedding between Love Match and Himari Shima, Haiyu would serve as the pastor officiating their 'marriage.' When Proto Zero-One in his MetalCluster Hopper form lost control, Haiyu was affected by the ensuing shockwaves and seemingly possessed by the will of the Veal. He tricks Hiroto Hayashi in order to gather information on the Hiden Metal. Haiyu had already scanned his Humagear Body Seal barcode with his own Progrisekey to help Mizu transfer his data to the Progrise Hopper Blade, but soon was forced to transform into the Arsino Mester by Hiroto. Later, he was rescued by Azuma as Zero-One MetalCluster Hopper, thanks to the Progrise Hopper Blade that was created by Mizu and was escorted by Mizu to a safe place.

## Personality

As a Humagear developed to work in the film industry, Haiyu worked hard and effectively memorized the script for the movie. Unfortunately, being a Humagear couldn't give him an experience of ad-libbing during the acting, which leads Haiyu to be bugged and try to reread the script to learn if the performance existed or not.

When he received the commentary from Shin, Haiyu tried to learn to adapt and improve.

By the time he was called upon again, his acting skills seem to have improved dramatically, as he was able to assume the role of a pastor and even pretended to be hacked by the Ark in order to trick Hiroto.

## Mester Form

**Arsino Mester**

> Zetsumerise!
>
> Transformation announcement, Kamen Rider Proto Zero-One

**Statistics**

* **Height:** 212.8 cm
* **Weight:** 138.9 kg

Haiyu transforms into the **Arsino Mester** by using the Arsino Zetsumerisekey in the Zetsumeriser.

**Arsenal**

* **V-Horn**: The split horn on the Arsino Mester's reinforced head. It fights by charging at the enemy with the V-Horn lowered.

**Abilities**

* **Humagear Hacking**: Using a method similar to transforming into a Mester, the Arsino Mester can corrupt other Humagear and transform them into Trilobite Mester by piercing them with tendrils.

**Appearances:** 11, 24

## Equipment

* Zetsumeriser
* Arsino Zetsumerisekey

## Behind the Scenes

### Portrayal

Haiyu Yamaguchi is portrayed by Sebastian.

### Etymology

* His name Haiyu means "actor" or "actress" in Japanese.
* The Arsino Mester is named after the ***Arsino**itherium*, an extinct genus of paenungulate mammals belonging to the extinct order Embrithopoda that lived during the late Eocene and the early Oligocene epochs in northern Africa.

## Appearances

* *Kamen Rider Zero-One (Fan Version)*
	+ Episode 10: *I Met an Actor*
	+ Episode 11: *Don't Stop the Camera*
	+ Episode 23: *Humagear's Love*
	+ Episode 24: *Dangerous Becomes Good*