This document summarizes the 1st place solution for detecting objects in images of classical and modern Japanese books for the National Diet Library of Japan. The solution uses an EfficientDet model with BiFPN and CenterNet to detect 7 categories of objects. It is trained on over 2000 images using focal loss, L1 loss, and data augmentation. Multiple models at different scales are ensemble using weighted boxes fusion to achieve mean IoU scores of 0.82340 for public and 0.84978 for private leaderboards.