During the research, I found out the story behind the banner. This was the banner put up after the Great East earthquake occurred on March 11th, 2011 in Japan. The earthquake triggered huge tsunami and
はこだて and どまくwere one of the great damaged districts.
The banner was put up in order to support the victims of the earthquake, and this campaign had been conducted around many places in hakodate area such as train station and wakoビル(see the links)
In this katakana sample, ｶﾞﾝﾊﾞﾚ was used as an emphasis. As the banner's goal is to support the victims, the phrase "cheer up!" was written in all three forms (hiragana, kanji, and katakana) to give more impression and emphasis.
The train connects Biei and Furano, center spots of Hukkaido island.
”ノロッコ” は a combination word of のろい (very slow) and トロッコ (an observation car). Since this train has a purpose of enjoying a scenery and fresh air of Hokkaido, as the word is meant to be, ”ノロッコ” must be used as an emphasis.
It is very interestingly written since ノ looks like an alphabet letter "J" and ロ looks like "O" - it almost looks like an English word.
Even a Japanese person said
"各車両のサイドにはシンボルマーク
カタカナでノロッコをデザインして有りますが、
外人には解読不可能でしょう。
私も一瞬考えました。" on his blog that it also took a moment for him to figure out the symbol/word.
While its roundish shape contradicts with sharp and straight lines of common katakana words, ”ノロッコ” might be written in such manners to symbolize and emphasize its meaning of "slow observation car".
Additional example that I found..
3. ワイシャツ
Tシャツ comes from T-shirts in English. But there is no Y-shirts. In Yシャツ, Y means "white." While "white" is used as ホワイト in Japanese, Japanese people changed to Y-shirts since it is a sound what they hear. They use as what they hear. Regardless of its color, ワイシャツ is commonly used all for men's dress shirts under suits or jackets. I thought it was very interesting because Koreans also pronouns white shirts as ワイシャツ.
