According to insiders, Kase and Toda only started getting closer after they reunited for the first time in 2.5 years for the filming of the WOWOW drama SP last year. During the press conference and completion screening of "Kono machi no Inochi ni" on 20 March this year, they both revealed that they could trust each other and work well together despite playing characters with a different type of relationship this time.
When the two of them were filming "SPEC", Kase was seeing actress Ichikawa Mikako while Toda was dating actor Ayano Go. After breaking up with Ayano, she was reported to be seeing Katsuji Ryo but they separated later. When asked about their relationship, both Toda's and Kase's agencies commented that this is their private matter and will leave things to them but did not deny the rumours.