The youngest sister, she is very apologetic. In the first fight, she uses her ship's shield as a battering ram, not unlike Madoka's usage of shields. However, she is seen to be apologizing throughout the fight. She pilots the Red Snapper Extra. She is comparable to Ayano, however Ayano seems to be more proactive than Erytron. Like the other Red Snappers, her name is an allusion to the color red. Her name is probably a Japanization of erythron, an element of the blood-forming system involved in the production of red blood cells.  (Source: Wikipedia)

In the year 2999: humanity is split into two factions, Terra and Ness, in a war fought by starships. One of the foremost of the pilots is the cocky teenager Yamamoto Yohko, and during one of her missions, she and her crew are sucked into a temporal anomaly (a la Star Trek) that sends her back to our time. Amnesiac, she only thinks of herself as a typical high school student - until a course of events sends her back to her ship the TA-29, with her newfound friends fighting at her side in a war that looks suspiciously like an arcade game (complete with 100 yen ignition costs!). 
(Source: AniDB)

Meet Yohko Yamamoto - a cat-eyed, 15-year-old girl in the late 20th century with a love for videogames and Pocky. Because of her exceptional talent with arcade shooters, she's been recruited by Lawson to travel a thousand years into the future to pilot the prototype ship TA-29. Together with Ayano Elizabeth Hakuhoin, Madoka Midoh and Momiji Kagariya, Yohko leads the Terran team against Rouge and Ness' infamous Red Snappers in this epic space adventure.
 
(Source: Anime News Network)

There is an ancient legend on a distant planet which states (among other things) that four goddesses will one day descend from the skies and all will be right with the world. 
Of course meanwhile, Yohko and the rest of the Terra team (with one straggler) have crashed on a backwater world, and they have to figure out a way off before their new charge... gets hungry again! 
Every so often, a celebration takes place in one of the most beautiful places in the Universe... a cosmic Sakura fest! Since the Terra Team has been doing so well, one of them is invited to join the high command as they meet their opposite numbers from NESS. It's a time of celebration and a time of peace... but it seems that someone didn't get the message. 
(Source: AniDB)

For the athletic and outgoing Yohko Yamamoto, life is all about grabbing her quarters and putting her skills to the test; which is why for her, piloting a space ship is as easy as playing in the arcade! Using a supply closet in their school as a portal through time, Yohko and her friends travel between the years 2000 and 3000, having fun adventures, battling in space, and becoming closer as friends.

Nisu no Meo-Eryutoron