If you click around enough on the options they have at the bottom it takes you to different chapters of the manga and such. If you also copy paste the Japanese title 小木くんのなつやすみ it takes you to a Twitter page you can navigate through different links where you can possibly buy the raws or where you can find them linked somewhere else. It takes a bit of work but it’s pretty doable.
This is the person’s account with different chapters but some of them are split up into multiple posts so it’s a bit of work to figure it out.
https://www.pixiv.net/en/users/16668725/artworks
If you click around enough on the options they have at the bottom it takes you to different chapters of the manga and such. If you also copy paste the Japanese title 小木くんのなつやすみ it takes you to a Twitter page you can navigate through different links where you can possibly buy the raws or where you can find them linked somewhere else. It takes a bit of work but it’s pretty doable.
Twitter page:
https://mobile.twitter.com/koikawa_orn