Rumi Wakui (和久井留美 Wakui Rumi?) is an idol available in THE iDOLM@STER: Cinderella Girls. Her basic card is Rare and it can be obtained via the Comp Gacha: Takane's Flower. She later received 4 Rare card sets plus a Rare+ card for the "Sparkling Bridal Show" event, 4 Rare card sets, and three S Rare card sets with the titles "Lovely Bride", "Mystic Blue", and "Refined Lady".
|Event||Prelim Rank||Final Rank|
|1st Anniversary Election||Unranked||Unranked|
|2nd Anniversary Election||Unranked||Unranked|
|3rd Anniversary Election||Unranked||Unranked|
|Voice Idol Audition||Unranked||48|
|4th Anniversary Election||Unranked||Unranked|
|5th Anniversary Election||Unranked||Unranked|
|6th Anniversary Election||?||?|
Rumi is a woman who sacrificed her personal life to put an office career before everything else. She avoided having a social life to dedicate herself to work advancement, and even cut her hair to a boyish length because she didn't want being feminine to be a career issue. Her ambition led her to become a company manager, but also forced her into being single.
Despite being allergic to them, Rumi really loves cats and can't avoid hugging them when she sees one.
In the tie in Cinderella Girls Theater skits, Rumi is often seen caring for her fellow idols, and takes on an almost motherly tone with Takumi Mukai and Tomoka Wakabayashi. Her love of cats often appears to get the best of her, causing her to have allergic reactions during lessons. She proves that she’s an extremely good tennis player, playing a competitive match that lasted well over an hour and 30 minutes with the Producer. Believing that she has lost her concentration she attempts to focus on flower arranging, but feels at a loss when she passes on the opportunity to pet a cat.