Japanese phones get left out of the conversation because these topics spin into nostalgia and the Western audience doesn’t have any experience with them. Likewise the JP discussion wouldn’t fondly remember all the Nokia variants.
On a side note I have a pet theory that Japanese cell phones helped push display technology forward. The English alphabet can be displayed very easily with limited pixels but kana and kanji cannot so there’s less pressure for Western manufacturers to innovate displays. For a phone to first be successful in Japan it needs a very high resolution display.