Gradual typing, proposed by Siek and Taha, is one of the attempts to integrate static and dynamic typing in a single language. Igarashi et al. proposed gradual session types, which extend gradual typing to binary session types. The language they studied is an extension of functional session types in which channels must be handled linearly. In this work, we propose a gradually typed extension of imperative session types, in which a single channel name is used more than once for communication. In this talk proposal, we describe an overview of our calculus, focusing on the delta over the previous work.