I’ll Tiki-Tiki You (For Reals) is Tiki’s first side story in Tokyo Mirage Sessions #FE Encore. The only requirement is that you finish another side quest.
I'll Tiki Tiki You (For Reals) Side Quest - Tokyo Mirage Sessions Encore
I’ll Tiki-Tiki You (For Reals) Guide
Bloom Palace
Talk to Tiki in the Bloom Palace and she will ask you to find Tiki=Waifu.
Shibuya
Go to Shibuya and enter the Cafe Seiren. You will hear two guys talk about Tiki=Waifu and that she disappeared near 106.
Illusory 106
Enter the Idolasphere Illusory 106 and teleport to 3F. Go to 4F and enter the big room to see a scene with Tiki=Waifu. Teleport back to the Bloom Palace and you will unlock Tiki’s Backup Skill Idola_Safety.exe. Field effects from items and skill will hold longer.