In , the "piece" you're looking at is a time-travel adventure that reveals one of the series' long-standing mysteries: how Natsu got the scar on his neck.
The group witnesses younger versions of themselves and other guild members, like a young Mirajane and Erza fighting over cake. Stai guardando FairyTail OAV 03 SUB ITA
In a humorous twist, it's revealed that the scar on Natsu's neck wasn't from a grand battle; he actually gave it to himself during a fight with his younger self while trying to erase the memory of a loss to Gray. In , the "piece" you're looking at is