- The first episode is surprisingly sad. Kouji and Shiro are longing in their living room, when the bell rings. Their caretaker Rumi goes to open the door as they remain seated. Shortly after they hear several horrified screams and bolt towards the main door only to find the corpse of the poor girl lying down on the floor, murdered by Baron Ashura...
- Shortly after, their grandfather calls them and asks him coming to his mansion very, very quickly. Kouji -with Shiro tagging along- rides his bike towards Mount Fuji, but when they arrive the mansion has turned into smoking ruins. Scavenging between the rubble, Kouji and Shiro find out a hatch leading towards an underground lab... and Professor Kabuto lying down a beam. The Professor is barely capable to tell them about Dr. Hell and Mazinger-Z before dying. Kouji and Shiro cry and Kouji vows he will avenge his grandfather.
- In one of the earlier episodes, a kid builds a tiny, robot-shaped toy and he declares happily it is like his "brother". Baron Ashura steals the toy (after mercilessly knocking the kid out) and uses it to try a size-changing ray. The robot becomes humongous, it begins destroying the city and Mazinger is forced to destroy it. Later the kid is sobbing, wondering why his "brother" killed so much people... and Koji gloomily reminds him a robot is a machine, and machines are not good or bad; they make what they are told. The episode ends up with the kid remembering his robot among sobs.
- Episode 15: An underwater mechanical monster (Glossam X2) is slicing ships in half. Lisa and Mary Gordon, the wife and the daughter of a an American scientist, are traveling by ship when Glossam attacks and splits the ship in two halves. Lisa manages reaching a lifeboat and she tries getting Mary up on it. However Mary woman realizes they are about of getting caught in the whirlpool, and she shoves the lifeboat away before sinking, effectively giving away her life to save Lisa's.
- In episode 46 Kouji, Sayaka and Shiro found a baby on a basket on the Institute's gates. A note written by his mother told his father died one year ago and she had tried to raise their son, but she had finally got sick and she could raise him no longer; so even though it hurt her she had decided leaving him where she thought he would be safe. Kouji inmediately rode out in the night to try to find her because they feared she was about to commit suicide... and he was right.
- Episode 90: Dr. Hell fabricates a cyborg resembles Kouji and Shiro's mother and sends it to the Institute. Kouji is suspicious, but Shiro is overjoyed. Later in the episode Shiro is forced to shoot her, in spite of the fact he is not sure if she is not his mother. Poor little Shiro.
- Mazinger vs Great General of Darkness: After the first strike of the Mykene Army, Koji is emotionally and physically wounded, Mazinger is wrecked, Diana is destroyed -again-, the Photon Institute is in ruins, and Shiro has nearly died after a ceiling fell on him. Koji is staring at a picture of his father (Kenzo) and his grandfather (Juzo), crying as he thinks he will die in the next battle, but he still will fight to try save lives.
- At the next day, several Mykene monsters are approaching. Kouji bolts towards Mazinger, stating loudly he knows he may die but he does not care:innocent lives are on danger, and he will fight on and on and when he finally is not able fight anymore he will die along Mazinger. Sayaka approaches to hand him over Shiro's birthday's present, and for one single instant it looks like if they are going to finally spit it out... but after several hesitant seconds, Kouji spins around and runs towards Mazinger (in the Gosaku Ota manga they do actually kiss). Not only it is a Tear Jerker, but it is also a Crowning Moment of Awesome.
- In the Gosaku Ota manga, Dr. Hell and his island took off spacewards and exploded out of the atmosphere. Everybody thought Kouji had died along Mazinger Z but in reality he had been rescued -again!- by Great Mazinger. Shortly after they met him again, obviously alive, and Sayaka rushed to hug him. However she noticed there was something odd with his body, and he revealed his body had been badly damaged, and he had been turned into a cyborg. Sayaka replied she did not care about that and he was still HER Kouji. And it is worth noting the person had saved his life by turning him into a cyborg was his father -right like Kenzo had been turned into a cyborg by his father Juzo-, although he did not find out until later.
- Several scenes in the Mazinkaiser movie, especially the both heartbreaking AND horrendous deaths of the twins Lori and Loru as well as their rendition of Dr. Morimori's Heroic Sacrifice..
- The Minerva X episode is memorably tragic, considering that she was a sentient mecha in love with Mazinger... and said love, obviously, is impossible. Not made much better by her being destroyed at the end, in an Heroic Sacrifice to save Mazinger and Kouji.
- Dr. Morimori's death. In ANY media.
- Everything about Lorelei and Shiro. Lorelei was the local New Transfer Student and daughter of a foreign Mad Scientist, or better said — a Robot Girl built by that Mad Scientist, who wanted to prove he was better than Dr. Kabuto, builder of Mazinger-Z and Shiro's grandfather; for that, he built an Humongous Mecha -Rhine X1-, and a Robot Girl -Lorelei- was meant to fuse with it to make it work. . What happened? When the scientist got a fatal wound, he confessed the truth to her and pleaded her to defeat Mazinger; determined to fullfil her father's last will, Lorelei merged with Rhine and challenged Mazinger to a death match, so Kouji was forced to fight and kill her. Poor Shiro was devastated after that.
- And let's not forget Erika the Robot Girl. She was an android built by Dr. Hell. However, she suffered from amnesia and had forgotten her origins. She genuinely believed she was a normal girl, and when she was told her true nature, she rejected it. And the end, she helped Kouji and she died cause it.
- There's also Sayaka's Heroic B.S.O.D. as Kouji almost dies after they have a fight and he goes into the battlefield without her support.
- The destruction of Aphrodite A definitely qualifies. Same goes to Sayaka having such an Heroic B.S.O.D. that she nearly commits suicide by drowning herself in the nearby lake, thinking that Aphrodite is there and is calling out to her.
- And now one of the biggest tearjerkers. Shin Mazinger Zero has the death of Koji Kabuto.... or rather the REPEATED deaths of Koji who all died in order to restart the timeline in order to save the universe from.... Mazinger itself. While most readers will be confused many longtime fans are sure to feel their heart fall apart upon seeing the robot that has saved the world COUNTLESS times.... now devolved into yet another mindless beast.
Tear Jerker / Mazinger Z
For a super hotblooded series, the is plenty of non-manlyTears to be shred.