Like a Dragon: Infinite Wealth - 61 - Substory 47: Certifiable Lover
After hanging out with Adachi and inviting Tanabe-kun to Dondoko Island in the process, and then visiting Julie and the Shrine, we head to Ounabara to chat with Maeda and give her an ABC Store Gift Set, then some Hawaiian Cosmetics, and then a Plumeria Bouquet.
I imagine you might need to have cleared all exams for it and I had an Intellect level of 9 when the icon popped up.
After that, Ikari will finally gather the courage to confess his feelings to Laura-chan and ask for Ichiban's support in it, but things won't go exactly as planned...
You don't get a direct reward for this substory, but talking to Ikari again afterwards will result in both him and Laura becoming potential guests on Dondoko Island!
Timestamps:
0:00 Inviting Tanabe-kun to Dondoko Island and seeing Adachi's Walk & Talk Finale
7:45 Starting the substory proper.