Remembering Those Sea Green Eyes | Chihiro x Haku

Chihiro x Haku
Chihiro has been living like a normal teenager for the past 5 years and her childhood is pretty much a blur except a few things including the spirit world. Although she sometimes thinks it was all just a weird dream or her young self imagining things, she tries and convinces herself it's real.
What happens when she ends up finding the tunnel leading to the spirit world once more?