One Japanese Twitter account,
@honoo_teppann  (炎の鉄板, or “The Red-Hot Grill”) is on a mission to promote this quintessential Japanese comfort food through retweets and lively conversation.
But first, a little explanation about okonomiyaki: A savory creation, okonomiyaki is difficult to describe to anyone who has never eaten it. As Japanese language and culture blog Tofugu says  in an excellent and encyclopedic entry on okonomiyaki:
Okonomiyaki is described many ways. “Crepe” and “omelette” are two common comparisons. But you’re bound to hear “Japanese pizza” or “Japanese pancake” most often. These descriptions are all true to an extent but basically wrong.
Generally speaking, okonomiyaki is a mixture of batter made from taro-root flower, lots of cabbage, meat, a teriyaki-like sauce, and a variety of condiments including mayonnaise and pickled ginger.
The tweet below helps convey how okonomiyaki is good over a flat stovetop, typically right in front of the customer:
焼くんじゃ・うちはなんと言ってもがんす入りお好み焼きです。がんすとは魚の練り製品で新次元のおいしさです。 pic.twitter.com/8PH7L1mZ 
— 炎の鉄板 (@honoo_teppann) February 7, 2012 
Let's grill! If we were to say one thing about our okonomiyaki it's that it incorporates a local Hiroshima delicacy called gansu . Gansu is a kind of processed fish popular in Hiroshima.
Osaka vs. Hiroshima: An Age-Old Rivalry
There are two generally recognized styles of okonomiyaki in Japan: Hiroshima-style and Osaka-style.
Osaka-style okonomiyaki tends to scramble all of the ingredients together when cooking. In Hiroshima, the different ingredients are added to the grill layer-by-layer.
Osaka, Japan's colorful and charming “second city, is generally regarded as the home of okonomiyaki. Twitter user
@honoo_teppann  aims to change that:
世界に誇る食文化「広島風お好み焼き(お好み焼)」を極める場所です。 作る人も食べる人も大歓迎。熱くokonomiを語りましょう […] Location: 広島市中区土橋
This Twitter account is dedicated to promoting Hiroshima-style okonomiyaki (the only true okonomiyaki) to the world. We welcome anyone who creates or consumes okonomiyaki. Let's all spread the word about okonomiyaki […] Location: Dobashi, Naka Ward, Hiroshima
Indeed, honoo_teppann frequently writes tweets about okonomiyaki from the cuisine's “ground zero”, Dobashi in Hiroshima.
— 炎の鉄板 (@honoo_teppann) April 17, 2015 
Introducing Okonomiyaki Yo Yo (Kaita , Hiroshima); Their okonomiyaki has a fragrant exterior with a fluffy texture. Yo Yo was opened ten years ago and has never lost its enthusiasm for making okonomiyaki. #okonomiyaki  #hiroshima 
【新規ご紹介店舗】http://t.co/4Enji3AUNZ  お好み焼 若貴（広島市中区紙屋町）辛口ソースに辛い麺、唐辛子のフライ、辛子風味のごまを使った「カープ焼」が一押し。#okonomiyaki  #hiroshima  pic.twitter.com/hz7fzydhpc  — 炎の鉄板 (@honoo_teppann) April 3, 2015 
Introducing Okonomiyaki Wakataka (Hiroshima CIty); Their okonomiyaki features a savory [as opposed to sweeter-tasting] sauce, topped with deep-fried cayenne peppers, spicy sesames… and called “Carp-Yaki ” [after the baseball team].
— 炎の鉄板 (@honoo_teppann) April 3, 2015 
Introducing Harumi (Hiroshima); Made especially in commemoration of beloved Hiroshima Carp pitcher Hiroki Kuroda , their signature dish is the “Kuro-yaki”. It's black in color [kuro means ‘black’ in Japanese] with a distinctive taste all its own.
For a definitive look at how to cook okonomiyaki from scratch, be sure to check out Tofugu's excellent article on the topic .