This article proposes a virtual reality (VR) system to equip knowledge and skill of the tuna dismantling, they have to learn it in hands-on style as well as in conventional lecture and self-study styles. However, high cost of tuna gives them less chances of the practical work. Therefore, a VR based system is proposed as a supplemental tool, in which the students can study and practice dismantling the tuna in a virtual space. The proposed system consists of PC, a HMD for VR and controllers for both hands. One controller is assumed to be a cutting knife, and the another is used for tracking the position of the other hand. The system encourages the user to cut the virtual tuna with the controller as the cutting knife. From position and direction of the knife when the knife is cut in, the system determines the correctness of the cutting. If the cutting is within normal range, the system represents the cutting and encourage the user to proceed. If not, the system give caution by message and/or vibration to the user and encourages him/her to re-cut in. The system has another mode called "test mode." In the test mode, the system gives no caution/hints to the user, while the system determines the correctness of the user's action (cutting). The accumulated determination is converted to score, so that the user can easily understand his/her level of achievement. Thus, the system is expected to be effective as a supplemental and continuous study tool.