Gameplay alters greatly from its sister franchise: it was the first, if not only, game in the series to have your player character be the idol rather than their producer. Picking one of the three rookies would allow you to play their "route", with storylines often intersecting every week. The game was also managed on a day-to-day basis rather than the weekly format of other installments, with the ability to change accessories and songs only available at the start of the week. This game also has the noteworthy distinction of being the first in the franchise to include a male idol, making Ryo (for a time) a rare breed to see.
Dearly Stars got a manga adaptation of its own split into three parts: Splash Red, focusing on Ai, Innocent Blue, focusing on Eri, and Neue Green, focusing on Ryo. All three parts got their own Drama CDs released alongside their respective manga.
This wouldn't be the last time we see the 876 cast: they make an appearance in ONE FOR ALL debuting as an idol unit, working under the name Dearly Stars. They would later have cameos as rival idols in other mainline iM@S games, as well as recruitable appearances in THE iDOLM@STER: Cinderella Girls. Ryo would later make his proper debut as a male singer in THE iDOLM@STER: SideM.
THE iDOLM@STER: Dearly Stars contains examples of:
- Beach Episode: Ryo's story features a chapter at the beach, where the 876 idols have a photoshoot.
- It does lead to a Hot Springs Episode when Ryo needs a break from posing in the feminine swimsuit.
- Butt-Monkey: Ryo's motivation for becoming an idol in the first place is to shed his girlyboy image and become more popular with the ladies. Naturally, his producer chooses to parade him onstage in a pink dress.
- Clark Kenting: Ryo's "disguise" consists of boob pads, make-up, and the removal of his glasses.
- Gaiden Game: The first game in the iM@S series to be one, in fact. It focuses on an entirely new set of idols that sign on some time after SP, and even includes some of the 765 idols after they got famous.
- No Indoor Voice: Ai Hidaka.
- Stacy's Mom: Ai becomes a victim of this. Her mother, an ex-idol herself, becomes nostalgic for the glory days when Ai makes it big and decides to make a comeback. Ai is shortly overshadowed in the public eye by her still incredibly hot mom.
- Super Title 64 Advance: Dearly Stars references the system it was originally released on.
- Wholesome Crossdresser: Ryo—well, not exactly. He didn't want to crossdress at all, and wants to debut as a male idol. Once he finally gets the oppurtunity to confess this, he eventually quits being the 876 version of himself.