No. 6

Nezumi learns from Karan's note that Safu was taken by the Bureau of Peace. However, he decides to hide this information from Sion and secretly request that Dogkeeper obtain information on the correctional facility. However, unbeknownst to Nezumi, Sion and Rikiga are visiting a used clothing store where Shion discovers Safu's coat that was smuggled from the correctional facility. Meanwhile, Safu is being treated as a "sample" by the researchers at the facility where she was taken. (Source: No.6 Wiki)