Masato Mishima

Masato Mishima (三島 正人) was the aide of ZECT HQ's leader, Riku Kagami. Masato was also one of TheBee Zecter users to transform into Kamen Rider TheBee (仮面ライダーザビー) temporarily after the defeat of Shun Kageyama. Later he was revealed as one of the true main antagonists of the series and used the form of Gryllus Worm (グリラスワーム) in episode 48 of Kamen Rider Kabuto.

In future Kamen Rider crossovers, he was presumed to be the one who used the powers of TheBee Zecter despite only transformed once, thus becoming Kamen Rider TheBee in the crossovers.

History
At times he does communicate with Sou Yaguruma and Shuichi Tadokoro to brief the ZECT teams about the Worms. Eventually, he was upset with Yaguruma botching a mission and Tadokoro questioning him about ZECT's agenda. There's implication that he has no faith in Kageyama as TheBee, despite Kageyama being loyal to ZECT and was looked down upon by Kamishiro. He has no sense of taste, and finishes eating by taking a supplement. He forcefully became TheBee at one time despite the TheBee Zecter's attempt to reject him. He truly thinks Kageyama was an eyesore because he can only complain and has lost the TheBee Zecter. He also seems to have a connection to Rena Mamiya/Uca Worm and had always kept the Hyper Zecter with him. Renge manages to steal the case with the Hyper Zecter, but Uca Worm takes it back only to find that the case has been rigged with a bomb.

Mishima tries to destroy the Hyper Zecter with the bomb. After the explosion, he taunts Tendou for failing to obtain the Hyper Zecter. However, he doesn't realize the power of the Zecter as it manages to find its way to Tendou, much to his chagrin. He then tosses his glasses to the ground in anger. He gradually loses respect for Riku Kagami's servile manner toward the Natives. After realizing Negishi found out about the Red-Shoes system, he makes a pact with Negishi and overthrows Riku Kagami as leader of ZECT. Using the Natives' pendants, he gains the ability to turn into Gryllus Worm, the strongest Native. He was defeated by Hyper Kabuto's and Gatack's Rider Kick and then destroyed by the meteorite explosion that obliterated the studio set.

35th Masked Rider Anniversary File
Mishima is one of a group of five characters from Kabuto who appear hosting the 35th Masked Rider Anniversary File, a collection of five featurettes shown during episodes 23 through 27 of Kabuto, this segment acted as a look back to the Kamen Rider Series and an early advertisement for the God Speed Love Movie.

Kamen Rider Kabuto: God Speed Love
Masato Mishima appears with a more minor role in the movie, being one of the members of ZECT's inner circle alongside Riku Kagami who has secretly sided with the Worms to construct the Jacob's Ladder station to allow the Next-Worms to invade. He later sends out Issei Kurosaki to stop Kabuto and Gatack when they board the station.

Rider War
Kamen Rider TheBee appears in the episode 1 of Kamen Rider Decade in the dream of Natsumi Hikari.

The Destroyer of Worlds
In the special version of episode 31, Kamen Rider TheBee is seen as one of the many Kamen Riders who fought in the Rider War against Decade and were all destroyed. They were presumably restored after the destruction (and subsequent revival) of Decade at the end of the Rider War and the worlds were restored.

OOO, Den-O, All Riders: Let's Go Kamen Riders
Kamen Rider TheBee was part of a group of reinforcement riders led by Akira Date/Kamen Rider Birth to aid the primary riders in defeating the Rock Great Leader. All the Kamen Riders got on their bikes and performed the All Rider Break attack which destroyed the Great Leader.

Kamen Rider × Super Sentai: Super Hero Taisen
The Gryllus Worm, resurrected again as one of the Great Commanders of the revived Dai-Shocker. Following the orders of Doktor G, Dai-Shocker's second in command, he engages GokaiPink in combat and they're evenly matched. The two evil organizations united and faced off against the combined forces of the Super Sentai and Kamen Rider Forces.

Super Hero Taisen Z
The Gryllus Worm was one of the monsters in the Space Shocker army which fought a combined force of Kamen Riders, and  as they approached the.

The Kamen Rider Rings
Gryllus Worm appears in the epilogue of Kamen Rider Wizard with the other monsters,later they found the Rider Rings and they meet later in the lair of Amadum

Neverending Story
Gryllus Worm appears again as among the monsters whom were destroyed a combination of Blade's Lightning Slash, OOO's OOO Bash and Agito's Rider Kick.

Kamen Rider Battle Rush
Kamen Rider TheBee appears as a playable and support character in the video game Kamen Rider Battle Rush using Rider Punch.

Personality
Mishima is a no-nonsense individual as a devout member of ZECT. While he gives high regard to his superior, he treats the rest of the ZECT members, especially Kageyama beneath him, that also includes outsiders like Tendou as well.

Forms
He only used the TheBee Zecter for a short period. In episode 48 of Kamen Rider Kabuto, he assumes the form of the strongest Native Worm, Gryllus Worm.

Devices

 * Rider Brace: TheBee's transformation brace
 * TheBee Zecter: TheBee's transformation device
 * ZECT Buckle: Clock Up belt

Weapons

 * Zecter Needle: TheBee's prick-stinger used to perform Rider Sting attack

Vehicle

 * Machine Zectron: TheBee's Rider Machine

Portrayal
Masato Mishima is portrayed by Tomohisa Yuge (弓削 智久), who previously portray Goro Yura in Kamen Rider Ryuki and would later portray Kiyojiro Bando in Kamen Rider Gaim.

As Kamen Rider TheBee, his suit actors were Makoto Ito (伊藤 慎) and Yoshifumi Oshikawa (押川 善文).