Both have characters who are exploring their identities, looking at feelings and attitudes - including outside pressures relating to cross-dressing, gender identity, and teenagers with same-sex crushes, and both have aspects of bullying.
Both star actor Araki Towa in a drama that includes him being lusted after by his teacher. Smells Like Green Spirit is BL while Shounen no Abyss is not.
Both depicts the life of LGBTQ individuals but in different generations and period of life. I genuinely like both and I can't pick which one is better but dang 2024 had good representation in Jdrama and Kdrama and I think these two are strong candidates.