So ChiHaru appear every week on HKT48のももち浜女学院 radio show...
Latest episode (130504) has them performing a ChiHaru duet version of Suki!Suki! Skip! Haruppi singing and Anai on the guitar
Suki!Suki!Skip to
11:22 for it!
(this link is direct to that timestep...)
reprise at this timestep:
They seem to sing other little bits throughout this show - it seems fun
Some past episodes:
130427
130420
130413