Abstract: This paper describes our systems that were submitted to the restricted
translation task at WAT 2021. In this task, the systems are required to output
translated sentences that contain all given word constraints. Our system
combined input augmentation and constrained beam search algorithms. Through
experiments, we found that this combination significantly improves translation
accuracy and can save inference time while containing all the constraints in
the output. For both En->Ja and Ja->En, our systems obtained the best
evaluation performances in automatic evaluation.