Background/Objectives: Mini-tablets have gained popularity as a pediatric dosage form owing to their high acceptability. Since 2022, the Showa University Hospital has prescribed acetylsalicylic acid (ASA) mini-tablets to pediatric patients with Kawasaki disease (KD). In this study, we investigated the real-world, at-home administration status of ASA mini-tablets in pediatric patients with KD. Methods: This retrospective study included 14 pediatric patients with KD on ASA mini-tablet therapy between November 2022 and October 2024. Medication administration completeness, mood changes during administration, administration patterns, beverages consumed, and swallowing-related events were analyzed. Associations between changes in the administration pattern or beverage consumption and swallowing events or mood changes were evaluated. Serious adverse events and coronary artery aneurysms were assessed using medical records. Results: Patients were prescribed ASA mini-tablets for a mean duration of 60.9 days. No serious adverse events or coronary aneurysms were observed. Among the 679 medication records, 5 swallowing-related events were identified. No mood changes following administration were observed in >90% of cases. The mood worsened to “Bad” once, with no further deterioration. The “All at once” administration pattern occurred in 64% of occasions across 12 patients (age: 9–79 months). Patients aged <3 years used medication-assisted jelly, whereas older patients mostly used water. Conclusions: ASA mini-tablets can be safely administered at home with minimal swallowing problems. Patients completed full doses irrespective of tablet number, age, administration pattern, or beverage, supporting ASA mini-tablets as an acceptable dosage form option for ASA in KD.