In the end, not only Cocoro and Maki got messages in their journals. So did Nico.
And so did Nozomi. Nico's and Nozomi's weren't as gentle.
Everyone stayed an idol, and no one dated an Uranohoshi girl, even though it turned out they all met Riko, and everyone remarked on how much she looked like both Maki Nishikino and Erena Todo. Then they were puzzled when she thought that Nico was Umi's little sister the way Yukiho was Honoka's and Aliasa was Eli's.
Honoka and Tsubasa got together and, while Honoka was jealous about Tsubasa flirting with every cute girl she saw, somehow it worked out.
Nico had a crisis of conscience, and showed her mother and her sister Cocoro the messages in her journal. Cocoro showed her own messages to them. Maki and Nico finally resolved to at least try a relationship. Amazingly, it worked fine. Yukiho ended up being the only girl to marry a boy, another idol, and they eventually moved to where Yukiho could take over ownership of the sweets shop.
Alisa and Cocoro found each other to be just fine, and Cocoro wondered idly sometimes if she was improving her lot or not.
The rest of the predictable pairings happened, and worked out fine. Once the skeptical Eli had been told the whole story (as much as Nozomi, Nico, Corocoro and Maki could tell her, in any event), she respected Nozomi's mysticism even more, and it was always an element of their time together.
All Rin and Hanayo were told was that Nico was a much more delicate, high strung, and under-pressure girl than anyone had realised. They ended up being a calming influence, and someone Nico could relax and have fun with.
Kotori had been pining for Umi all along, and they eventually formed a duet.
Alisa performed with Yukiho (for a couple of years) and Alisa, to much acclaim.
Nico tended to perform solo, but often performed with Maki in the summer. It was her parents' hospital, so Maki could set her own hours. Maki watched Nico carefully for her stress levels. They found a management group that would steer people who wanted to involve Nico with drugs away.
As of 2023, all of the Muse members were happily married. Most of them had moved to Hokkaido. Eli, Umi, Kotori and Nozomi opened an idol school there, and all the other Muse members and the Alisa, Cocoro, Yukiho trio were visiting teachers at different times.
Nico let Cocoro substitute for her in several numbers during the Muse 10th anniversary concert. For a spotlight-obssessed girl like Nico Yazawa, it was hard to come up with a better expression of gratitude.
Meanwhile, in another time, another life, that was perhaps going to vanish, Maki and Cocoro were in Hawaii saluting each other for things nearly no one would ever learn about.