because usagi didn't remember anything. that's why usagi still wants to find about her dad's death
what I understood is Usagi didn't know about borderland's truth and She consider Ryuji's method (which is exploring to borderland) is the best way to resolve her depression. but the main idea is Usagi didn't know the borderland is death game. only Ann knows borderland clearly
the timeline between cheese world and strawberry world is insane, I STILL CAN'T PROCESS IT
dont process it. just enjoy it. so in the future if u want to rewatch, you still can enjoy it because you don't remember anything in the first place wkwkwkwkwkwkwk
but the main idea is Usagi didn't know the borderland is death game.
only Ann knows borderland clearly
about romance : yes included
Fe₂O₃ + 3CO → 2Fe + 3CO₂
but for Mg + ZnSO₄ → MgSO₄ + Zn, it's a chinese joke : "nǐ de měi tōu zǒu le wǒ de xīn".
the meaning is : Your beauty stole my heart
Mg + ZnSO₄ → MgSO₄ + Zn
= Mg stole Zn
Mg = Magnesium = 镁 (měi)
Zn = Zinc = 锌 (xīn)
Mg + ZnSO₄ → MgSO₄ + Zn
wkwkwk the creator is creative
and
Mg + ZnSO₄ → MgSO₄ + Zn
wkwkwkwk
but if you need me to answer seriously, it's more like an open ending.
still too many possibilities