Kobo Park Miyagi is known as the home of baseball team the Rakuten Tohoku Golden Eagles, so it was with surprise that we learned an entirely different avian had taken up residence: the Black Eagle!

Fellow fans now routinely report sightings of Kurowashi-san around the stadium on game days.

Fellow fans now routinely report sightings of Kurowashi-san around the stadium on game days.

OK, so the “Black Eagle” in question isn’t actually a bird. It’s a man, aged 51, who goes around wearing a headdress resembling a large black raptor. He’s quickly become the baseball club’s most prominent fan, and his support for the team – “interspecies,” though it may be – appears to work wonders. In five of the six matches at which he’s appeared, the team has won.

So who is this mysterious man? Unfortunately, Kurowashi-san, as he’s known (“Mr. Black Eagle”), is not much of a talker. When questioned, he limits his responses to phrases scrawled in a notebook he carries with him in a plastic bag. And even then he doesn’t say much. When asked what he likes about baseball he answers simply, “home runs.”

With his resplendent headpiece and steely gaze, Kurowashi-san has quickly become a fan favourite at Kobo Stadium.

With his resplendent headpiece and steely gaze, Kurowashi-san has quickly become a fan favourite at Kobo Stadium.

Such reticence has some suspecting that he actually doesn’t know much about baseball – a suspicion strengthened by his stone-faced reaction to pretty much everything that happens on the field, except of course home runs, which he celebrates by standing up ramrod straight and waving his Rakuten Eagles flag.

He also appears to like peanuts. There are reports of several occasions when they’ve been confiscated as he tried to smuggle them into the stadium in a plastic shopping bag (fans aren’t supposed to bring in food). Even this indignity doesn’t arouse much of a reaction, though.

Why the 9604 jersey-number? Spoken out loud, 9-6-0-4 sounds similar to the word "Kurowashi" in Japanese.

Why the 9604 jersey-number? Spoken out loud, 9-6-0-4 sounds similar to the word “Kurowashi” in Japanese.

Nevertheless, with his resplendent black eagle headdress, he can’t help but attract attention, and fellow fans now routinely report sightings of him on social media. He’s generous with accepting selfies too, though not with smiles. In most photos of him online he exhibits the same deadpan look.

Kurowashi-san’s popularity prompted the Rakuten Eagles in May to anoint him as an official team mascot for so-called “Black Eagle Days,” special home ground match days for which the team dons its black third jersey. Kurowashi-san accepted the honor with appropriate gravity, promptly printing himself a business card: “Kurowashi, Official Character, Tohoku Rakuten Golden Eagles,” it says. He now happily hands it out to fans.

Readers keen to get acquainted for themselves with the Rakuten Eagles’ most enigmatic fan should note two dates in their calendar: Aug 6 and 20, the next two Black Eagle Days. Given Kurowashi-san’s track record, you can probably look forward to an Eagles’ victory, too. Just don’t expect Kurowashi-san to get excited about it. Unless of course someone hits a home run.