CD Lost Smash

The CD Lost Smash (voiced by Kaho Takada) is a CD-themed Smash that was used by Misora Isurugi who's the daughter of Soichi Isurugi who works with Sento Kiryu by using her ability to purify Fullbottles. Often secluding herself in nascita's basement, she is more well-known as the online idol Mii-tan (みーたん Mītan), using her huge following of fans to help her seek out and collect information. She later uses the CD Fullbottle to briefly become the CD Lost Smash.

In her childhood, her father Soichi Isurugi would often read to her. Misora would point out several things of her liking, which would eventually become the basis of Kamen Rider Build's Best Matches.

Misora was just a young girl when the Skywall Disaster caused her to fall into a seven-year coma, thus unlocked her Fullbottle purification ability. She was admitted into the same mental hospital as her own father, which later after a month, Soichi (who was possessed by Evolto), escaped and kidnapped her into Faust where she believed she was purifying bottles for good. However she realized the evil intentions of Faust and lost the will to purify any more, so Soichi escaped with her back to Nascita where she was convinced by Soichi to purify the bottles for good. To this day, she remains in nascita's basement in hiding because she is still wanted by Faust.

Misora was briefly held hostage by Massugu Ubukata, only to be flattered when he called her cute.

On the eve of the proxy battle between Touto and Hokuto, Misora was entrusted by Sento with a killswitch he had created to break the Hazard Trigger should he go berserk, at the cost of his life. Spectating the event, Misora was unable to follow Sento's request even as his rage threatened to kill Grease. Thankfully, Banjo, having been called by Sawa, intervened at the last moment and saved the lives of both Kazumi and Sento.

Later, she was kidnapped by Evolto, who turned her into the CD Lost Smash.

During the Build Annihilation Plan, both Misora and Sawa were among the Japanese populace whom had been compelled by "Kengo Ino" to eliminate Sento. Eventually, however, they were freed by the influence of Vernage. With her bracelet, Misora combined the Gold Rabbit and Silver Dragon with the Genius Fullbottle, allowing Sento and Ryuga to become Kamen Rider Build Cross-ZBuild Form and defeat Kamen Rider Blood.

After Sento defeated Evolto for good, the new world was successfully created. This world’s version of Misora now working with her dad at Nascita and first shown serving Kazumi and his underlings drinks, only to be startled by Kazumi's infatuation for her. Shortly afterwards, Sento arrives at Nascita and orders a coffee. Misora saw Sento's face and said that she had a feeling that they have met before, although Misora didn't remember Sento's name. Her dad instead exclaims that Sento is Taro Satou and asks for an autograph. Misora is last seen berating her dad to continue on working, while at the same time mimics one of the Tsunagizu moves and catchphrase.

Eventually as the alien Killbas forces Ryuga to open Pandora's Box with the white Pandora Panel, memories from the old timeline resurfaced in Misora's mind, due to exposure of the Nebula Gas. She and the rest of Team Build reunited with Sento and Ryuga.

Misora was shown to be aloof, and rather lazy. Usually, she talks in an almost monotonous tone and uses short words. However, once she assumes her alter-ego Mii-tan, she's shown to be a total opposite from her usual, gloomy demeanor. Ever since the war between Touto and Hokuto, her lazy personality seemed to have disappeared and she seems to be more active. This is probably because she hasn't made any Fullbottles ever since Sento made the RabbitTank Sparkling Fullbottle.

It is revealed that her shut-in personality stems from being secluded from society for so long, as she tells Ryuga during their "dates". She always wanted to live a normal life, however, her power to purify Fullbottles makes her unable to do so. To this day, Misora openly states she didn't want the power.

Misora cares deeply for her allies, especially Sento and Banjo as she would always try her best to help them out with their own problems. Although, she is rather cold towards Kazumi for being her fanboy & Gentoku for his ridiculous fashion senses.

She also still cares for her dad unconditionally, even after knowing her father is Blood Stalk. When she finally found that Soichi is possessed by Evolto, she becomes enraged at Evolto while demanding to give her father back. Although, she still believe in his word to help Sento.

However, when Misora was possessed by Vernage, she'll turn sarcastic and sharp-mouthed, although her speech also carries a sense of royalty and dignity due of Vernage being the Queen of Mars.

Original

 * Fullbottles Purification: Misora has the unique ability to purify Fullbottles that receives Smash materials to make them compatible with the Build Driver using her unlockable Golden Bracelet. This ability drains most of her energy, and she herself states that she'll fall unconscious for one week after doing so. This special ability is synchronized with Misora's willpower. Misora explained that when she purified Fullbottle, she saw a vision of Mars during it's destruction. When she think strongly that Earth didn't have to suffer the same fate, the purification succeeded. However, for it to work, Soichi had to trick her into believing that she was using her powers for good, so that she would purify Fullbottles willingly; also Misora ​​was able to purify the Nebula Gas that surrounded Ryuga Banjo by the Sclash Driver.


 * The bracelet, notably, has an effect on a Hazard Form in Berserk mode, causing it to become a double version of one of the Fullbottles used for the match. This manage to knock Sento to his sense for a while and cancel his transformation. This effect would later become the basis of the FullFull RabbitTank Bottle.