Monsters is a one piece prequel for a character named ryuma that takes place around 400 years before the events of one piece Plot: (7/10) Dragons exist in the world and terrorize cities, Ryuma the main character is a swordsman and goes around helping ppl. Animation: (8/10) The animation is solid wish one piece could have this lvl of animation as well sine the start Characters: (7/10) Ryuma, he is a mix of zoro with luffy and a very good swordsmanCyrano, this guy thinks he is mihawk
Flare, she looks like nami

Overall: (7/10)
for a 20 min ova its great even if you arent a one piece fan i would suggest you give it a chance