This study investigates L2 acquisition of bound variable interpretations of Japanese demonstrative pronouns (so-series DPs) by L1 English speakers. It is known that overt pronouns cannot take a bound variable interpretation in null subject languages (the Overt Pronoun Constraint in Montalbetti, 1984), nevertheless, Japanese so-series DPs, including sono '(of) that', indeed take a bound variable interpretation (Hoji, 1991; Noguchi, 1997; Kurafuji, 1998). In contrast, the English demonstrative that generally does not allow the interpretation, with some exceptions. 30 L1 English speakers of L2 Japanese were compared with native Japanese speakers in interpreting sono in two tasks. The results suggest that the intermediate-level L2ers accepted the bound variable interpretation of sono significantly less frequently than the controls, and instead showed indications of transferring interpretation of the English demonstrative. Nevertheless, the advanced-level L2ers accepted the bound variable interpretation of sono fully, which is indicative of support for the Full Transfer/Full Access Hypothesis(Schwartz & Sprouse, 1996).