Post-it notes are great problem-solving tools. However, physical Post-it notes have limitations: surfaces for attaching them can run out; rearranging them can be labor-intensive; documenting and storing them can be cumbersome. We present Post-Post-it, a novel VR interaction system that overcomes these physical limitations. We derived design requirements from a formative study involving a problem-solving meeting using Post-it notes. Then, through physical prototyping, using physical materials such as Post-it notes, transparent acrylic panels, and masking tape, we designed a set of lifelike VR interactions based on hand gestures that the user can perform easily and intuitively. With our system, the user can create and place Post-it notes in an immersive space that is large enough to ideate freely, quickly move, copy, or delete many Post-it notes at once, and easily manage the results.