Unused. There are no noticeable scratches. Please refrain from purchasing if you are concerned about initial scratches, etc. (Will be shipped in simple packaging.) Instant purchase O.K. Price reduction O.K. The Most Efficient Study Method to Achieve Maximum Results in the Shortest Time ★★★Author's Fastest "200,000 Copies" Sold! DaiGo's Scientific and Evidence-Based "Study Method That Really Works"! ★★★ While studying at the Faculty of Science and Technology at Keio University, he researched artificial intelligence memory materials science and explored the human "mind." At the same time, he introduced the British-born mentalism to Japanese media for the first time, and as Japan's only mentalist, he performed unique performances on numerous television programs. After that, he shifted his activities to business and academics, successively acquiring impressive titles such as business advisor for companies, product developer, author, and university professor. He has written a series of best-selling books, and the total number of copies issued has already exceeded 3 million.