*NOTE: Recommended level is 53.
Obtained: Tiki’s last side story becomes available after completing the first trial in Chapter 6. Once you defeat all four of the bosses, you’ll receive a Topic from Tiki. After you read it, head to Bloom Palace and speak with her.
After the cutscene, head to the map transition in Fortuna Office to receive more instructions on how to create a song for Tiki. Chrom suggests speaking to Tiki=Waifu so head to Cafe Seiren in Shibuya and enter through the door to trigger a cutscene. During the cutscene, you learn that Tiki=Waifu might have wondered into the 106 Shibuya Idolasphere so head on over there to check it out! Teleport to B3F then head down the stairs to reach the boss room on B4F. When you enter the door, a cutscene will trigger and you will face Cervantes (level 55), Platinum Swordmaster (level 54) and Regal Paladin (level 58). Cervantes is fond of his Attribute Shift skill, which changes his weaknesses. Focus your attention on Cervantes as he will just keep spawning adds as they die. Defeat Cervantes to trigger a cutscene then head back to Cafe Seiren to speak with Tiki=Waifu who is inside the cafe. After you complete the song, head to Bloom Palace and let Tiki listen to it to trigger a cutscene and complete the quest.