**Hometown:** A Kind World
**Height:** 149 cm

Neurotic and contradictory, Riamu is a follower of the Menhera subculture and an idol otaku. Riamu makes the decision to become an idol due to her desire to quit school and as an attempt to turn her life around since Riamu fears aging out of her teenage years and feels she has hit a dead end in life. Riamu uses the catchphrase yamu ("I'm so sick"), and frequently makes references to the fact that she is lonely and depressed, as well as desperate for any kind of attention. Riamu seems to have incredibly low self-esteem and does not see herself as having any good points.

Riamu utilizes a lot of current otaku internet slang, primarily from Twitter. Riamu is terrified of being hated and begs her fans to be nothing but kind to her, but at the same time states that she doesn't care if she causes controversy as long as she gets attention and sells. Riamu's Valentine's Day 2019 lines imply that she thinks people coming to hate her in something inevitable, so she wants to receive as much love and attention as she can from them before it happens.

Riamu seems generally distrustful of idol otaku, despite being one herself, stating that she doesn't trust otaku who change the idol they support, and that she only has faith in otaku who attend events and concerts in person. She seems suspicious of idol otaku who claim to support every idol in a group (known as daredemo daisuki or DD), because she does not believe they will actually pay attention to Riamu herself. It can be inferred that these attitudes likely stem from Riamu's low self-esteem and her desire for her fan's undivided attention and support.

The U149 in the title refers to the aspiring idols at the center of it all: These small girls are ready to make it big! All under 149 centimeters tall, this group of aspiring pop idols dream of performing for thousands of people. But with zero experience, they’ve got a lot of work to do. Not to mention there’s a distractingly cute prince in town! With the help of their rookie producer, who’s just as short, can they stay focused and make it to the top? 
(Source: Crunchyroll, edited) 
 

Note: Announced during DAY 2 of "THE IDOLM@STER CINDERELLA GIRLS 10th ANNIVERSARY M@GICAL WONDERLAND!!!" final tour concert, a TV anime adaptation of the spin-off manga THE iDOLM@STER Cinderella Girls: U149.

A special commemorating the 10th anniversary of the THE IDOLM@STER Cinderella Girls franchise. The anime features all 190 idols from the series. 

Note: A 6-minute preview "Celebration Animation" of ETERNITY MEMORIES was released on November 28, 2021, first unveiled during Day 2 of "THE IDOLM@STER CINDERELLA GIRLS 10th ANNIVERSARY M@GICAL WONDERLAND TOUR!!!: Celebration Land" live concert. 

The video was reuploaded on September 7, 2022 onto the IDOLM@STER Channel, correcting spelling, omissions, and credits on the initial upload that was on YouTube.

__Height:__ 155 cm

[Twitter](https://twitter.com/Hoshiki_seena) | [YouTube](https://www.youtube.com/channel/UC_gDRXFTXc5ljEBamxlBIMg) | [Wiki (jp)](https://ja.wikipedia.org/wiki/星希成奏)

She was a member of the idol group [AOP](https://anilist.co/staff/150932) until their disbandment in 2021.

On September 30, 2022, it was announced by her agency that she had been diagnosed with acute lymphocytic leukemia and would be taking a hiatus from voice acting and performing to receive treatment. On May 10, 2023, it was announced that she had been discharged from the hospital and will gradually return from her hiatus.

Music video for the song Seikan Sekai celebrating the 6th anniversary of The IDOLM@STER Cinderella Girls: Starlight Stage mobile game. Animated by studio KAI.

The anime will stream exclusively in the The IDOLM@STER Cinderella Girls and The IDOLM@STER Cinderella Girls Starlight Stage smartphone games.

Irregularly serialized in The IDOLM@STER Cinderella Girls social mobile game app itself, this "cute, comical" manga follows the idols' "real" daily life that can only be found in these panels.
 
(Source: Anime News Network, edited)

Music video for the song Go Just Go! celebrating the 5th anniversary of The IDOLM@STER Cinderella Girls: Starlight Stage mobile game. Animated by studio CloverWorks.

Assorted commercials for The IDOLM@STER Cinderella Girls: Starlight Stage mobile game. 
 
1)【デレステ】5周年CM　夢見 りあむ 篇【アイドルマスター】(17 Sep 2020) 
2)【デレステ】5周年CM　一ノ瀬 志希 篇【アイドルマスター】(17 Sep 2020) 
3)【デレステ】5周年CM　佐藤 心 篇【アイドルマスター】(17 Sep 2020) 
4)【デレステ】5周年CM　北条 加蓮 篇【アイドルマスター】(17 Sep 2020) 
5)【デレステ】5周年CM　大槻 唯 篇【アイドルマスター】(17 Sep 2020) 
6)【デレステ】2021年お正月CM 新春特番篇【アイドルマスター】(31 Dec 2020) 
7)【デレステ】2021年お正月CM 初詣篇【アイドルマスター】(3 Jan 2021) 
8)【デレステ】6周年CM Let’s Launch 篇【アイドルマスター】(2 Sep 2021) 
9)【デレステ】6周年CM Starlight Party 篇【アイドルマスター】(2 Sep 2021) 
10)【デレステ】6周年CM New Dawn 篇【アイドルマスター】(5 Sep 2021)

Riamu Yumemi