日 (Day) vs 目 (Eye) vs 白 (White) vs 百 (Hundred) vs 自 (Self)
Box-shaped N5 kanjis are the #1 source of early reading mistakes. A single stroke at the top changes everything.
5-Second Radical Distinction Rule: 日 (1 inner bar = Day/Sun) • 目 (2 inner bars = Eye) • 白 (sun with a ray on top = White) • 百 (one 一 on top of white = Hundred) • 自 (eye with a nose ridge on top = Self).