A point of warning -- if you fight a battle and Totori's level is above Gino's, he'll run away to train (and raise his level). Just keep him in the party, whatever his friendship is, then toss him (forever!) when you make it to 15. That way, you can avoid the event -- provided you do not, even once, use Gino in battle after that.
After Year 2, 1/1 go to an area with Gino. Upon returning to the workshop, Totori will come up with a recipe for his super move. Make the Key Item (Gino Level 10+, 40 friendship)
After meeting Sterk, but before he can be in the party, talk to Gino. He wants to be Sterk's apprentice. This event, bizarrely, can happen in a search area without Gino in your party. (45 friendship)
7 days later, go to the Square. Gino talks about Mel behind her back, and it doesn't end well for him. Possibly optional?
15 days after the 45 friendship event, go to Atelier Totori for an event with Sterk and Gino.
3 days later, go back to the Square for more begging. Aaaand Sterk caved.
7 days later, go to the Wharf. Sterk lost to someone, but I'm of the opinion that he just lost to a bomb.
After Year 3, 1/1, go to Atelier Totori. (Gino Level 15+, 50 friendship) This event may be influenced by having Sterk in your party, so don't panic if it doesn't appear for several months.
Go to the Square. Or, super obsessive completionists, go to Artisan's Way for a different background picture.
Talk to Gino. Poor Gino.
After Year 4, 1/1, an event (and easy fight) will occur in Atelier Totori. Two more events will occur here, each 7 days apart. The second is attached to the ''Chilvarous Defender'' trophy. (Gino Level 25+)
To stop the final event from happening, simply do not level Gino to 25.