He's Expecting

Both dramas are about mpreg (male pregnancy) where the ML gets pregnant (in GXLGXDGZ ML has an artificial womb implanted without his knowledge, while in HE it's an unexplained cis male pregnancy) and must face the prejudice and discrimination that comes from being pregnant.

Both are social commentary on women's problems and pregnancy in general, but He's Expecting takes on a more serious, respectful, and heartfelt approach while in GXLGXDGZ it's more of a revenge comedy. Both MLs are judgy guys that are humbled (tho in GXLGXDGZ he doesn't learn his lesson).

Both are Japanese productions focused on social commentary through the lens of a pregnant man (in HE it's unexpected while in SF,iaR it's intentional).

Reverse gender roles. Both dramas revolve around the idea of what it would mean if men where confronted with situations women face. While Hiyama Kentaro no Ninshin deals around the idea that male pregnancy was as likely to happen as female pregnancy, Ooku emphasises on what it would mean if males where put into the roles women faced in ancient historic times.
Both are very bizarre productions but make one question about societal standards and norms.

The other half of me and you is set in a world where all the gender roles are reversed (however, the women still are the ones getting pregnant)

While very different plots, both explore gender roles in a semi-futuristic society in which some event (male pregnancy vs. almost no males) has occurred. Both are offbeat dramas with a heartwarming vibe.

Both MLs get pregnant and give birth (one supernaturally, the other more realistically). Both FLs are strong and hard-working.

- Gender role reversal themes in both (matriarchy and mpreg in BM, mpreg in HE)
- Mpreg
- Douchebag ML that becomes a better person
- Social commentary on gender discrimination

in BM the ML travels to an alternate universe where all gender roles are reversed while in HE the ML gets unexpectedly pregnant in the real world.

- Gender role reversal
- Alternate universe where men can get pregnant (Mpreg)
- FL is a douche that invalidates ML's feelings
- Social commentary

Both dramas are set in the near future where something has happened and some men are now able to get pregnant.

- Social commentary, specifically about feminism and gender roles
- Male focused
- Healthy male friendships
- Gender role reversal (househusbands in SM, mpreg in HKnN)
- Both include a place for these unconventional men to congregate and support each other
- ML who's initially opposed to the reversed gender role situation but learns to accept it and ends up liking it.
- Girlboss x Malewife vibes
- Themes of learning, acceptance and gratitude
- Both short japanese dramas

SM is a fluffy episodic-format minidrama while HKnN is a more serious regular formatted drama.