The hiragana you meet after the first 46.

You learned the 46 hiragana and figured the alphabet was done. Then you opened a real sentence and saw characters with two little marks in the corner, a tiny っ sitting where a full one made no sense, and a small ゃ stuck onto the side of another character. It feels like the goalposts moved right after you got there. They did not. What you are looking at is not a second alphabet. It is a small set of changes layered on top of the characters you already know.

There are really only four things happening here, and once you see them as changes to familiar shapes rather than new symbols, the pile gets a lot smaller.

The two marks that flip a sound

Those two little strokes in the top corner are called dakuten. They take a character you know and voice it. か becomes が. さ becomes ざ. た becomes だ. は becomes ば. The shape is identical. Only the sound shifts, and it shifts in a consistent way, so k turns to g, s turns to z, t turns to d, h turns to b. You are not memorizing twenty new characters. You are learning one rule and applying it to shapes you already read.

The little circle

は also takes a small circle instead of the two marks, and that gives you ぱ. This one is called handakuten and it only shows up on the は row, turning h sounds into p sounds. So は ひ ふ へ ほ become ぱ ぴ ぷ ぺ ぽ. That is five characters following one rule, on shapes you already read.

The small character stuck on the side

When you see a small ゃ ゅ or ょ attached to another character, the two are read as a single blended sound. き plus small ゃ is kya, not ki ya. し plus small ょ is sho. These are called combination sounds and they trip people up only because the second character is written small and easy to miss. Read them as one beat, not two.

The small tsu that makes you pause

A small っ does not make its own sound. It tells you to hold the following consonant for a beat, like a tiny stop. きって is not ki tsu te. It is ki with a held pause before te, which is why it sounds like kit te. Once you know to watch for the smaller size, it stops being confusing and starts being a useful signal.

Why this is easier than it looks

You already did the hard part when you learned the base 46. Everything above is a handful of consistent rules riding on shapes you can already read. That is why it pays to see the modified characters right next to the plain ones instead of on a separate list. が next to か, ぱ next to は, きゃ next to き. Put them side by side and the change is obvious and the sound follows from it. I am a visual learner, so seeing the small mark or the small character in place, against the original, is what made these click for me rather than treating them as brand new things to cram.

A simple way to get them down

Do not sit and drill dakuten in isolation. Read short words that use them, so the rule shows up in context and you get used to spotting the marks at a glance. See the word, try to say it before you confirm, then check. That small moment of producing the sound yourself is what makes it stick, far more than staring at a chart of modified characters.

If you have the base 46 down and want to fold in the rest without it feeling like starting over, SimplyHiragana runs on that see it, say it, check it loop and it is free. Learn the 46 shapes first. The marks and the small characters are the easy part that comes after.