With Shinichi I only ship him with Kaito and vice-versa but with Ran I want her to have a chance to dip her lesbian fingers in many pies wink wink. She deserves it.
Anyway, thinking about Ran becoming smitten with Aoko when they meet at a heist. Aoko is being harassed by the more hardcore fans of KID because of her protests against the thief and it's clear she is very outnumbered and cornered and Ran comes to her rescue.
Aoko takes Ran to a cafe as thanks and shares her woes about how she is always treated like that at KID heists and Ran is upset to hear that, she shares some of her less than stellar encounters with KID and has fun hearing Aoko's anger at the thief over it (Kaito, you've knocked her out multiple times and has tried to grope her before, unlike Sonoko and Shinichi, she is not your biggest fan). They bond over more subjects and Ran is very happy to leave the cafe with a new friend (and a growing crush)
Ran is very enamoured by the passion Aoko shows towards her KID protests and so whenever she's attending a heist with Shinichi and Sonoko, she'll find Aoko and act as her bodyguard against any of the more insane fans. Aoko too is happier to have someone in her corner for a change and if Ran looks very hot when she's threatening men who are trying to intimidate Aoko, she's not going to complain.
Soon Ran and Aoko are meeting beyond KID heists, just having the time of their lives together and growing closer and closer. Aoko is the one to make the first move, placing a kiss on Ran's cheek after one such day and soon after they're introducing each other to the other's childhood friends
(Which may or may not result in Kaito and Shinichi finally admitting their feelings for each other outside of a heist).
Aoko still dislikes KID but she can be thankful for his heist, if only because it let her meet Ran.