Not to be confused with the rather more famous Ryujo.
Ryuho, initially built as the submarine tender Taigei, is an interesting case. One of several auxiliary ships that the Japanese built with the express intention to convert to light aircraft carriers. And, arguably, one of the least successful...in terms of combat service. The Japanese considered this ship of dubious utility, and held her back from combat.
Does that mean Ryuho was useless? No. Far from it.
She found a role akin to American escort carriers, in ferrying planes to distant bases. While the Japanese would ultimately lose the war, this role was quite important. And in spite of her light construction, Ryuho proved quite resistant to damage. She ultimately survived the war, despite suffering some pretty severe hits at different points.
That's something, I think.
Further Reading:
https://www.amazon.com/WarshipsImper...
https://www.amazon.com/BattleHistory...
https://www.amazon.com/ImperialJapan...
https://www.amazon.com/ImperialJapan...
http://www.combinedfleet.com/Taigei_t...
http://www.combinedfleet.com/Ryuho.htm