One of the first milestones in learning Japanese is mastering ひらがな and カタカナ: you need this for reading anything meaningful outside of a textbook. There are 50 of each—五十音—and those are all the kana you'll ever see in print.
Until you open a can of ヱビス (Yebisu) beer (pictured) or pour a finger of ニッカウヰスキー (Nikka Whisky), and watch an episode of 日常 (Nichijou) by あらゐけいいち (Keiichi Arawi). Your friend sends you a snap of 京都ゑびす神社 (Kyoto Ebisu Shrine) and how come nobody ever told you about these extra kana?
ゐ, ゑ, ヰ, ヱ (Wi and We in hiragana and katakana) used to be fully functional kana. In the Nara period (710 to 794 CE), for example, the name 新井 was pronounced あらゐ, distinct from あらい. A few centuries later, pronunciation shifts caused ヰ to merge with イ, and ゐ with い. In 1946, Japanese officials declared ゐ, ゑ, ヰ, and ヱ as obsolete.
あらゐけいいち, the creator of 日常, spells his name in hiragana only, a rare practice among Japanese. The old surname matching あらゐ (新井) is now pronounced あらい, and that name is fairly common.
ヱビス Beer uses the obsolete ヱ (we) kana, but is romanized as Yebisu, and pronounced "Ebisu". The Ebisu (恵比寿) district of Tokyo is named after the Yebisu brewery that started in that location in 1890.
However, both the beer and the district are named after 恵比寿, or ゑびす, the god of fishing and commerce. He's one of the Seven Gods of Fortune (七福神), and the only one of wholly Japanese origin; he's depicted on the Yebisu label. Kyoto's 京都ゑびす神社 also is dedicated to Ebisu.
Writing reforms are not unique to Japan: the English word amœba long ago shifted to amoeba as œ fell out of fashion. But Japan has effected, and decided against, a number of reforms over the years:
Even as a foreigner learning the language, I'm glad Japan did not banish kanji from Japanese. All manner of literature, signs, photos and the like, old and new, would still have kanji; and frankly, longer sentences without kanji are harder to read: