Made In Abyss
メイドインアビス (original)
Located in the center of a remote island, the Abyss is the last unexplored region, a huge and treacherous fathomless hole inhabited by strange creatures where only the bravest adventurers descend in search of ancient relics. In the upper levels of the Abyss, Riko, a girl who dreams of becoming an explorer, stumbles upon a mysterious little boy.
Starring Mariya Ise, Miyu Tomita
It's a animation and drama show, and has a rating of 8.4 out of 10 from Imdb which is very high for this kind of show.
Watch it here
Not found streaming from United Kingdom.