Tomonori Maeda of the Carp was hit by a pitch last week from Masaya Emura and broke his wrist. He had surgery on Thursday and will likely be out for three months. Maeda is 41 and there may be some question about whether or not he simply retires at this point.
Here's video of the HBP (H/T Japan Ball Blog). The benches cleared, but I think the only actual fighting was when the Carp's pitching coach Kenji Furusawa went after Swallow's pitching coach Daisuke Araki. Furusawa was ejected.
Here's a card of Maeda that I brought back from Japan last month. It's a gold signature parallel of his card from the 1999 Calbee third series (#232):
(Got game details from Yakyu Baka)