1. Deaths by Sealing Techniques: The Hokage of Hidden Leaf Village have often died using sealing techniques. The Fourth Hokage sealed the Nine-Tails and sacrificed his soul. The Third Hokage used the same technique to seal others, resulting in his death.
2. Deaths in Battle: Some deaths in Naruto are particularly unfortunate. The powerful Third Raikage was killed by weaker ninjas. The Second Hokage died during an ambush by Kirigakure shinobi alongside the Third Raikage.
3. Deaths by Poison: The Third Kazekage, known as the strongest Kazekage, was turned into a puppet and killed by Sasori using poison.
4. Deaths by Genjutsu: Yagura, the previous Three-Tails Jinchuriki, was controlled by Tobi using genjutsu and died shortly after being released.
5. Death by Bite: The First Hokage, Hashirama Senju, was bitten by Madara during their battle, resulting in his death. The most unfortunate death in Naruto is the Second Hokage's death in battle, overshadowed even by the death of his brothers. It remains a regretful circumstance.