1997 Japanese Pokémon Amada Hyper Sticker: This establishes it as one of the many collectible stickers produced by the Japanese company Amada Printing Co. during the early years of Pokémon popularity. The stickers were a common alternative to trading cards and were sold in blind boxes. The Hyper Sticker Collection Part 2 is a specific, vintage set from 1997.

#387: This is the specific identifying number for the Mewtwo sticker within its set.

Prism: This indicates the rarity and finish of the sticker. Prism stickers are a type of holographic or prismatic foil that reflects light in a distinctive, colorful pattern, making them rarer than standard non-holographic stickers from the same set.

CGC 8: This is the professional grade assigned by the third-party grading company, CGC. A grade of 8 is considered Near Mint/Mint, meaning the sticker is in excellent condition but may have very minor flaws like light surface wear, a slight print defect, or very minor corner/edge wear.

POP 5: This is a crucial detail for collectors. It highlights the scarcity of the item in that specific grade, indicating that as of the last update to CGC's public database when the card was graded, it was one of only five copies that received a grade of 8. This low population can significantly increase its value to collectors.