Visit the library to discuss books with her; specifically, look for a book via the office PC first.
: Use your PC to find a specific book, then go to the library to talk to Mika about it to advance her route. Happy Summer v0.5.0 PC
: Character locations change based on the time of day. For example, Rosie might be in her room in the morning or watering plants in the hallway later. Character Progression Tips Primary Actions for Progression Rosie Visit the library to discuss books with her;
: After reaching relationship level 4 with Rosie, an illness event may trigger the next morning, requiring you to interact with Lucy in the kitchen to resolve it. For example, Rosie might be in her room
Watch TV in the living room, go to the gym together (requires buying a gym outfit on the PC), and talk to her when she is using her laptop.
For more specific walkthroughs and level-up requirements, players often refer to community-maintained tutorial guides on Scribd . Happy Summer 0.2.7 Tutorial Guide | PDF - Scribd