Err...How can I answer chinozo on the gossipup? I have almost touched everything interactive...
Sorry for the late reply! You can start that event by accessing the laptop in Ayumu's bedroom, opening GossipUp from the desktop and switching to the messages tab within it, which you can find near the top of the screen. You'll find the message from Chizuru there, and you can start the event by replying in the evening.