In our world, Sekibanki is a rokurokubi youkai who lives hidden among the humans in the Human Village... but in the Gensokyo of eternal summer, she lives freely on the beach! "Well, well, if it isn't Kogasa! Get ready to lose another baseball match to yours truly!" Apparently, this world's Sekibanki is engaged in a fierce beach-baseball rivalry with Kogasa Tatara, the karakasa-obake. It seems Sekibanki's prideful nature and tendency to keep others at arm's length have transformed into a positive desire to show off her baseball skills.

Sekibanki plays beach baseball in a way that only a rokurokubi can. She forms a one-woman team by controlling her nine Banki-heads, comprised of her original head and eight duplicates. Batting and pitching both require arms and legs, so Sekibanki's body takes care of those. However, since all nine Banki-heads look the same, she often has trouble keeping track of which head is covering which area of the field. "Banki-head 3, why are you defending the left? I told you to cover second base! ...What do you mean I'm Banki-head 3?!" To make matters worse, some of the Banki-heads aren't all that interested in playing baseball.

Sekibanki's greatest strength as a youkai is her ability to make her head fly, which she can remove and duplicate up to eight times (making nine in total). Controlling them at will to secure victory in battles of bullets is what she's best at. She carries her pride as a rokurokubi into every bullet baseball match, too. With her nine Banki-heads, she's able to cover all defensive positions, and she has unbound confidence in her abilities as a pitcher. "Banki! I'm hitting a home run off your next pitch," taunted Kogasa. "Are you sure? 'Cause I feel like there's a strike coming!" grinned Sekibanki in response.

At first, Sekibanki was annoyed by Kogasa calling her Banki and challenging her to bullet baseball matches. Perhaps it was due to overexposure to the endless summer's heat, but as they played match after match, Sekibanki began to get more and more serious about winning. The reason Kogasa first thought to get Sekibanki into baseball was because of her ability as a rokurokubi, which allowed her to cover all defensive positions alone. Even if Kogasa assembled a team, there'd be no baseball matches without an opponent to play against. At first, she saw Sekibanki as simply an unskilled practice partner, but now, she recognizes her as a serious rival.

In the past, Sekibanki had coveted being alone and professed not to need any friends, which is why she chose to hide the fact she was a youkai and live in secret in the Human Village. However, as she spent more time with Wakasagihime and Kagerou, she came to view them as dear and indispensable friends. Sekibanki has made it a general rule of hers not to be friends with humans or youkai. But here on the sunny shores of the summer Gensokyo, Kogasa may find her way onto Sekibanki's short list of exceptions.