This study investigates the extent to which Japanese learners of English as a Foreign Language (EFL) are able to offer mediation to their peers while engaging in pair work, and whether that mediation is sensitive to the needs of their partner. Grounded in sociocultural theory, the study assesses the extent to which the study participants identify and respond to a partner's developmental level, offering appropriate help. Further, evidence in the data of learner development is examined. Six first-year university learners of EFL participated in the study, and were placed into three pairs. Each pair was given a set of pictures in random order, and was asked to construct a story from the pictures, first orally, then in writing, working together closely with their co-participant. The audio-recorded sessions were transcribed and analysed for instances of developmentally sensitive peer-peer assistance. Numerous examples were found throughout the data showing all study participants being capable and willing to offer such assistance to their peers. Further, evidence was found of the assistance leading to microgenetic development in task performance.