Pawn tier · Enthusiastic Beginner · no fixed opening
Yuki is twelve, has been playing for a few months, and loves every part of the game except waiting. She moves pieces toward whatever looks interesting, often bringing her queen out early to chase something, and she has no set reply to your first move, so each game starts differently. That freedom cuts both ways: she never steers you into prepared lines because she has none, but she also has no plan to fall back on when the position goes quiet.
She is happiest in loose, open positions where pieces fly around and something is always hanging, ideally yours. What unsettles her is a calm opponent who develops, castles and lets her run out of ideas. Once her early energy stops producing threats, she starts shuffling pieces and leaving them on undefended squares. Treat her as a friendly sparring partner who rewards basic discipline, and remember that she does spot a free piece when you leave one.
At 600 ELO, Yuki plays like a real club player at that rating: she sees simple threats but still leaves pieces hanging and misses tactics two or three moves deep. Check every capture she offers, and look for loose pieces after each of her moves. Most games at this level are decided by the first clean tactic, not by the opening.
Yuki has no opening book: every move comes from the engine at 600 ELO, so no two games start the same way. Develop your pieces, castle, and punish the loose pieces Yuki leaves behind.
Yuki builds the habit every later rival punishes you for lacking: checking for hanging pieces on both sides before each move. She also teaches you to turn a material lead into checkmate without handing anything back.