Bleach: Watch Closely, This Is How You Use a Zanpakutō

"Still working on fireworks?" Masatsuki Aozaki looked at the woman before him in surprise.

The woman had a striking figure, a headscarf tied around her head, and long black hair parted into two sections. A tattoo of the kanji for "空" (Sky/Empty) adorned her left arm, and a long smoking pipe was tucked into her waistband.

This was Kūkaku Shiba, younger sister of the current Shiba family head and, in truth, the real power behind the clan.

Not that it mattered much—there were only four people left in the family who still carried the Shiba name...

She called it fireworks research, but Masatsuki didn't see any blueprints or designs. The only thing different was the smooth, pitch-black sphere sitting in front of her.

"The gunpowder formula you taught me has significantly increased in power—no residue, no smoke. When combined with Reiatsu, it could even be used as a weapon."

Kūkaku smiled slightly.

"I really don't know how you come up with these ideas."

Masatsuki shook his head. "Honestly, I have Lieutenant Sasakibe to thank. He's passionate about Western culture and gave me a lot of inspiration."

Thanks to Chōjirō Sasakibe's fascination with the West, the Soul Society had never been affected by the two-century-long isolation policy of the World of the Living. In fact, even centuries ago, when Sasakibe was still young, he had begun embracing Western influences, never once breaking that connection.

While the Soul Society's technological development took a different path than the World of the Living's, books on chemistry and physics could still be found.