Living with friends is one thing. Living with a robot friend is another. But to live with a robot friend with a passionate mission is a category of its own.
"Robo-kun? You better not request me space launch hardware right now."
This is perhaps the conclusion of our unnamed co-protagonist, who is characteristically clad in a pink rodent-like kigurumi. 'Shoujo-chan', as she is only known in the entire short series, is an acquaintance of a rather perky robot, the main protagonist who is also simply referred to as 'Niji-kun' 'Robo-kun'.
Inspired by what seemingly looks like a classic 80's era giant mecha anime on TV, Robo-kun decides to think big, and become a mechanical ally of justice. There one obvious disadvantage for our eager-to-be mecha hero though: he is technically a simple consumer electronic product, specifically designed to sprinkle water to create artificial rainbows.
"Like, try shooting your head up into the sky and we'll see what happens."
As the kigurumi girl puts it, he is only capable of making his head fly off. Understandably, this did not discourage our brave Robo-kun from trying to accomplish his dream. He then launches a series of objectives based on Shoujo-chan's loose suggestions, with varying degrees of failure at each step:
"Robo-kun, I did say to see what happens, but this is becoming really unpredictable."
First, he attempted to become a record holder for the highest head jump possible. This was after it accidentally thwarted a robbery with its head up into the sky.
"Wait, aren't wrecking balls supposed to swing sideways?"
Second, he tried to become a heavy work robot. He was initially accepted into the job, but after he was laid off by his boss, the following events afterward eventually placed a huge risk on the city itself.
"Silly. There's no rain that doesn't stop you know. On Earth, at least."
Third, at the request of Shoujo-chan, Robo-kun sets out to fulfill his intended design of showing a rainbow. His determination turned into an obsession in the end, however.
"You're cleared for launch Robo-kun! But you're not clearing any clouds with that."
Fourth, with torrential rains that seem to just go on and on, Robo-kun was inspired by a TV segment to be launched into the upper atmosphere. It then becomes part of a sensational TV segment itself.
"Oh shoot! Robo-kun accidentally witnesses how easy it is to make a rainbow!"
Fifth, Robo-kun was introduced to Shoujo-chan's friend, another robot (with 悪, or evil, written on its chest) who seems capable of doing everything he couldn't do with flying colors. The struggle to find the meaning of being helpful thus began.
"Ah, you guys beat me to it. But Merry Christmas anyway!"
Sixth... well nothing really important happened on Robo-kun's part. But he did earnestly prepared a delightful seasonal surprise for his dear friend. With the assistance of Mr. Evil Robo of course. Shoujo-chan meanwhile...
"Robo-kun, remember the saying to always use your head? Well this is your chance!"
Robo-kun's final attempt at glory was a battle of epic proportions. Like, literally, just as how he had always been fantasizing the moment since watching the mecha show. The twist, however, lies within Shoujo-chan herself, and the implied revelation of the events chronologically set before the animated short even began.
There isn't really much to say about Bomahead (formerly ロボと少女（仮）), in terms of timelines, or events, or even the production of the show itself. Each independently made episode ran only around a minute and a half, and ended by the ninth episode. Basically you can watch the entire series in under 20 minutes.
What we can definitely conclude though, is that Shoujo-chan being the secondary, indirect inspiration for Robo-kun was more than just a partner. The moments they shared together eventually defined the series. And with its themes, the show becomes surprisingly a lot more wholesome than one would initially expect.
Plus, the entire series is available officially on YouTube! (credits to the original creator)