It was Shinobu's birthday and you actually forgot. In fact, most of the Hashira forgot, including Shinobu herself.

Therefore, the second you found which was currently afternoon,you dragged her away from her work for a moment.

"What's so important that you..—" Her voice trailed off when you suddenly gave her a birthday cupcake while telling her happy birthday.

"Thank you." She smiled genuinely for once when she realized what's your objective here.