I found this walkthrough on the dev's dl-site page. It was in Japanese, but this is google translator's automatic translation of it. It sounds pretty solid and fairly easy to understand.
★ happy ending
・Collect a lot of money
・With the collected money, go to the back of the mountain hut at night and buy a Hercules beetle from the uncle.
・Go to the forest and exchange bugs with the boy
・At night, talk to the man behind the pigsty. Convenience store during the day → Sea → Talk to the man behind the pigsty at night
・Go to the bottom of the map by boat in Kodakara Village and get a fish
- Talk to the village cat and get the key
・You can get a rope in the night forest by talking to the office worker in the office in front of the station.
・Once you get an old sparkler from the barn, eat 3 times at the ramen shop.
・Go to a shrine and talk to an old man to exchange sparklers.
・ In that state, August 7th will be reached
* Nojiri route
It will run automatically if you do nothing.
* Hiroshi route
Talk to Hiroshi at the shrine on the night of August 4th
★ Kamoda Gonzo Route
Go to school on August 5th and talk to Natsuka. And
the Kamoda Flag, who agrees, will eliminate the Nojiri-Hiroshi route.
* Hidden END
Nojiri:
Chase the suspicious person by August 6th (The location is to help a girl at the station while working with Natsuhana/Go alone at night to Kodakara village → school → station square → park and talk to the suspicious person)
On August 18th, talk to the classmate in the upper right corner of the shopping district map, go to the ramen shop and get the item Examine the rock in the mountain hut with two items.
Hiroshi:
On August 17th, when you talk to the garbage cleaner in front of the shrine in Kodakara Village, a
garbage disposal site will appear on the map. So he gives the item he got to the shrine cat.
Kamoda:
Get items at Kamoda's house on August 16. Talk to the teacher in the shopping district in the evening.