Hiragana in depth
The order of the chart has a purpose
The chart is always recited in the same order: あいうえお, かきくけこ, さしすせそ, and so on up to わをん. That order is called gojūon, «the fifty sounds», although fewer are used today, because two old signs from the わ row fell out of use after the war. It is not just any order: it is the one followed by dictionaries, address books and any sorted list in Japan, the way we use the alphabet. Learning it in rows, and not sign by sign, saves searching your memory.
And it serves the grammar. Japanese verbs change their last syllable by moving along a row of the chart: 書く (kaku) gives 書かない, 書きます, 書けば and 書こう, which run through the whole か row, with a, i, u, e and o. Anyone with the chart in their head sees that conjugating is moving within a row, not a list of loose endings to memorise. That is why the chart is not left behind after the first week: it is the same grid the verb forms are explained on.
Diacritics, compound syllables and the small っ
The signs with diacritics are not studied as new ones: they come from adding marks to the ones you already know. The two little strokes voice the consonant (か and が, さ and ざ, た and だ, は and ば) and the circle turns the は row into a «p» (ぱ). Then there are compound syllables, written with a small や, ゆ or よ after a sign from the i column: きゃ, しゅ, ちょ. They sound like a single syllable, and the size changes the word: きょう is «today» and きよう, «skilful».
The small っ works differently: it makes no sound, but lengthens the consonant after it with a brief pause, as if gathering momentum. きて is «come» and きって, «stamp»; さか is «slope» and さっか, «writer». That pause takes up a full beat in speech, just like ん and long vowels, and it is the difference that is hardest to hear at first. It pays to say the pairs out loud, exaggerating the pause, until your ear tells them apart on its own.
How to learn it without getting overwhelmed
Two rows a day is a good measure: today's and a review of yesterday's. Read each sign aloud while you write it, because that fixes shape and sound at the same time. It helps to invent an image for the ones that will not stick, but what really settles them is reading them inside words as soon as possible: ねこ, さかな, ありがとう. And some groups get mixed up and are worth looking at together: ぬ and め, る and ろ, わ, れ and ね, さ and き, は and ほ.
In Hanasuka hiragana has its own section with three tools. The listing shows every sign with its reading and its tally of correct answers. The quiz asks how each one is read, choosing from four or typing, in rounds as long as you like and with no speaker until you answer, so the sound does not give the answer away. And tracing lets you draw them with your finger or the mouse. Since each character keeps its own tally, you can filter by the ones you are halfway through and do a quiz with just those.