ww

https://www.mangago.me/tag/Amnesia/

https://www.mangago.me/read-manga/false_memories_lee_gpiee/

https://www.mangago.me/read-manga/amnesia_doesn_t_make_me_your_boyfriend/
https://www.mangago.me/read-manga/kowagaranai_de_soba_ni_ite/ (highly recs)
https://www.mangago.me/read-manga/imitation_happy_life/
https://www.mangago.me/read-manga/negai_kanae_tamae/
https://www.mangago.me/read-manga/shounen_no_kyoukai/ (highly recs)
https://www.mangago.me/read-manga/mou_ichido_nando_demo/ (highly recs)
https://www.mangago.me/read-manga/my_dear_deadman/
https://www.mangago.me/read-manga/moritat/
https://www.mangago.me/read-manga/trace_of_you/
https://www.mangago.me/read-manga/nani_mo_iwanai/
https://www.mangago.me/read-manga/hotel_phryne/
https://www.mangago.me/read-manga/vampire_and_hunter/
https://www.mangago.me/read-manga/paid_fujoking/
https://www.mangago.me/read-manga/umi_de_hirotta_kimi_ni_sasagu/
https://www.mangago.me/read-manga/blue_cheese_table/
https://www.mangago.me/read-manga/therapy_game/
https://www.mangago.me/read-manga/nemuri_otoko_to_koi_otoko/
https://www.mangago.me/read-manga/shuchu_ni_otoshite_iidesuka/
https://www.mangago.me/read-manga/tale_of_the_yellow_dragon/ (highly recs)

To be honest, Some of these stories (mainly BL) have a rather plain/ bland storyline + roller coaster (IMO) except for the one with "(highly recs)". But hopefully, they'll fit your taste~ (=｀ω´=)