If you want to read the 'Tensei Shitara Slime Datta Ken' light novels legally, my go-to is buying the English editions from Yen Press. They hold the official English license for the series (you might see it under the English title 'That Time I Got Reincarnated as a Slime'), and they offer both print and digital formats. I grabbed a couple of Kindle editions during a sale and later picked up a battered paperback to toss on my shelf — there’s something delicious about flipping through the art and extras in the physical releases.
Beyond Yen Press, there are a handful of mainstream ebook stores that carry the official releases: Amazon (Kindle), Kobo, Google Play Books, and Apple Books. For the Japanese digital editions I’ve used BookWalker — they sell both Japanese and English versions depending on what’s licensed and available in your region. If audio is more your vibe, check Audible or your national audiobook services; sometimes official audiobooks are released for big titles like this.
If you prefer not to buy, your local public library or library apps like Libby/OverDrive are surprisingly good. I’ve borrowed light novels that way before; it’s legal, convenient, and a great way to preview whether you want to invest in a full set. One last practical tip: watch for publisher sales or bundle deals — I saved a ton on early volumes during a holiday sale, and the money went straight to supporting the creator and people who worked on the translation. Happy reading — Rimuru’s antics are even better when you know you’ve supported the official release!