Sorry if my 'definition' or jRPG sounds offensive to jRPG fans, but when i read 'jRPG", i 'visualize' a ultra linear history of a generic swordsman teenager saving the world with other teenager after farming the same monster for 60h+.
I don't see any jRPG showing mature content. Wen i mean mature, don't necessary means "fan service", means complex ethic decisions, dark themes like Slavery in Morrowind, they don't let you customize your main character, you need to be a immature teenager swordsman in 99% of time. That is exactly the opposite of NWN1 for example. In nwn1 you customize your character any way that you wanna, and play the OC with a sorcerer, then a druid then a paladin are completely different experiences because each class is so different. You can choose everything, age, gender, religion, skills, race, class...
The first game that i have played was M&M VII and my english was terrible(my grammar and accent still not good but at least i can undestand). Took an eternity to leave Emerald Island, but i loved everything. From the party customization to explore the island and get new spells, advance skills, try to get loot to sell. Was amazing. After a lot of time i got a PS1 and the first JRPG that i have played was FF VII. Dropped before i have completed the disc one. Found the game too repetitive and on rails.
I see a lot of jRPGs being released on steam and on gog and... Only i never liked a single jRPG? When i mean jRPG, i don't include RPG's developed in Japan with mostly "wRPG" characteristics like Dragon's Dogma.